I'm sure the sexual abuse at the hands of her father & uncle had NOTHING to do with her decision to enter porn 
It seems that sexual abuse on women from their male relatives tends to hyper sexualize the woman...turning them into "nymphos"...Playboy Playmate Nicole Narain had a similar issue.
But, that being said, people make their own decisions in life. Sure, they can be influenced by traumatic events in one's life. Jenna went into porn, and her and her father marketed her image, and make millions. So, she made millions off of her image...an image that possibly is rooted in her "alleged" abuse.
And if it is true about the abuse, it puts the story of Howard Stern asking her father if he could identify his daughter's (Jenna) vagina (I guess by pictures, on camera, and her father said yes), into a different, yet very sick light.