First of all this picture is clearly a father and daughter who's age we don't know.
Second of all of Muhammad's wives were widows. His first wife was 45 years old when he was 25 years old. She was a widow. If he were after lust he could have married hundreds of virgin wives before Islam. Before Islam there was no limit to wives. Yet he chose to be married to only one wife, a widow and 45 years of age, while it was absolutely common to have 'tens of wives'. This proves that it had nothing to do with lust or sexual urges, etc...
Thirdly, Muhammad (pbuh) set the criterion by establishing that the earlier a woman can marry is when she enters past puberty.
Fourthly and lastly no one had a problem with Muhammad (pbuh) marrying her. The whole 'young girl' this that arguments are no more than say 40 years old.. MAYBE actually more like last ten years. Why? Lets take a look
Lets look at some facts:
Richard and Isabel how old were they? The king and queen of the british? She was 7 years old.
Most of Europe used to 'marry' before puberty. The English, French and German nobilities used to marry all in this age.
Shakespeare anyone? How old was Juliet and Romeo? According to her mother she should stop being 'playful' and be married with children. If I recall this phrase right, she was 12 or 13 years old? Take a guess how long it takes to make that many children and be married?
Which brings me to the last point. This whole western phenomena of sexual promiscuity and avoidance of marriage, raising the 'age of consent' etc... comes in the late 1800s only. As I've come across a few different historical studies on this subject. Girls wanted to 'have fun' and no longer cared about marriage or sanctity. This is even more true today where children male and female are raised to be consumers and into 'having fun' well into their 30s. Teens the girls 'beautify themeslves' and get spoiled, 18+ they really start engaging in sexual experimentation, drinking, clubbing, etc... The focus on marriage and family is not there. This is reality.
On the other hand women of the past and men... were raised with the mindset of how to progress in life being able to work, take on responsibilities, etc...all from a young age, being rulers, kings, queens, warriors, students/scholars, workers, etc...
Just 100 years ago according to George Mason university:
Age of Consent Laws | Annotation 
 Information on the ages used historically in western age of consent laws is not readily available. This table has been compiled from a combination of historical and contemporary sources. By 1880, the first date chosen, many western nations had established an age of consent for the first time, typically of 12 or 13 years. By 1920, when the influence of reform campaigns that established a new link between the age of consent and prostitution had run its course, most had revised their age upward, to 14 or 15 in European nations, and 16 in the Anglo-American world. In the last decades of the 20th century, states and nations with ages below those averages amended their laws to move closer to them. In Europe that growing conformity owed much to moves toward greater European integration. Given that the rationale for the age of consent has remained essentially unchanged in its emphasis on the need to protect 'immature' children, the table highlights the shifting and various definitions of childhood employed across time and cultures.
 | 
Source
Date compiled from the following sources: Hirschfeld, Magnus. The Homosexuality of Men and Women. Translated by Michael Lombardi-Nash. Amherst, New York: Prometheus Books, 2000; Killias, Martin. "The Emergence of a New Taboo: The Desexualization of Youth in Western Societies Since 1800." European Journal on Criminal Policy and Research 8 (2000): 466; Odem, Mary. Delinquent Daughters: Policing and Protecting Adolescent Female Sexuality in the United States, 1885-1920. Chapel Hill: University of North Carolina Press, 1995; "Worldwide Ages of Consent," AVERTing HIV and Aids, www.avert.org/aofconsent.htm (accessed November 29, 2007).
Age Limit in Age of Consent Laws in Selected Countries
    1880   1920   2007
Austria   14   14   14
Belgium   -   16   16
Bulgaria   13   13   14
Denmark   12   12   15
England & Wales   13   16   16
Finland   -   12   16
France   13   13   15
Germany   14   14   14
Greece   -   12   15
Italy   -   16   14
Luxembourg   15   15   16
Norway   -   16   16
Portugal   12   12   14
Romania   15   15   15
Russia   10   14   16
Scotland   12   12   16
Spain   12   12   13
Sweden   15   15   15
Switzerland   various   16   16
Turkey   15   15   18
Argentina   -   12   13
Brazil   -   16   14
Chile   20   20   18
Ecuador   -   14   14
Canada   12   14   14
Australia         
New South Wales   12   16   16
Queensland   12   17   16
Victoria   12   16   16
Western Australia   12   14   16
United States         
Alabama   10   16   16
Alaska   -   16   16
Arizona   12   18   18
Arkansas   10   16   16
California   10   18   18
Colorado   10   18   15
Connecticut   10   16   16
District of Columbia   12   16   16
Delaware   7   16   16
Florida   10   18   18
Georgia   10   14   16
Hawaii   -   -   16
Idaho   10   18   18
Illinois   10   16   17
Indiana   12   16   16
Iowa   10   16   16
Kansas   10   18   16
Kentucky   12   16   16
Louisiana   12   18   17
Maine   10   16   16
Maryland   10   16   16
Massachusetts   10   16   16
Michigan   10   16   16
Minnesota   10   18   16
Mississippi   10   18   16
Missouri   12   18   17
Montana   10   18   16
Nebraska   10   18   17
Nevada   12   18   16
New Hampshire   10   16   16
New Jersey   10   16   16
New Mexico   10   16   17
New York   10   18   17
North Carolina   10   16   16
North Dakota   10   18   18
Ohio   10   16   16
Oklahoma   -   -   16
Oregon   10   16   18
Pennsylvania   10   16   16
Rhode Island   10   16   16
South Carolina   10   16   16
South Dakota   10   18   16
Tennessee   10   18   18
Texas   10   18   17
Utah   10   18   16
Vermont   10   16   16
Virginia   12   16   18
Washington   12   18   16
West Virginia   12   16   16
Wisconsin   10   16   18
Wyoming   10   16   16
How to Cite This Source
Stephen Robertson, "Age of Consent Laws," in Children and Youth in History, Item #230, http://chnm.gmu.edu/cyh/teaching-modules/230 (accessed October 2, 2012).
So according to the above the average age of consent/marriage/sex age in america one hundred years ago was 10 years of age across america. The lowest was 7 years of age in Delaware USA.
Edit:
One more point to add. After Muhammad (pbuh) passed away, Aisha even led armies, she had the ability to say what she wanted. If Muhammad (pbuh) ever wronged her she could have said something.
She is also responsible for a huge portion of transfer of knowledge of Islam
Muhammad (pbuh) used to tell people, if you want to learn about Islam go to Aisha (pbuh) as she had an amazing ability to learn and memorize.. and not only that, but to rationalize and have understanding of the knowledge. Being Muhammad (pbuh)'s wife, she also had detailed and intimiate accounts of Muhammad (pbuh)'s wife and how he conducted himself. Thus she was responsible also for transfering much knowldge in regards to how Muslims should conduct themselves if they are to follow Muhammad (pbuh)'s example and way of living.
And finally yes, she is responsible for majority of our knowledge of Islam, many hadith (sayings) regarding Muhammad (pbuh) and his actions.
We call her the mother of the believers, as we call all the wives of the prophet (pbuh). Also she used to get jealous of Muhammad (pbuh) mentioning Khadija his first wife 
