OK, so she's 160 but she's been 120 before. That means she can get there again.
It may be hard, but she needs to make time for HERSELF in order to accomplish this.
If she doesn't train at all, she's going to need to do some exercise, even though I am sure the kids keep her pretty busy. Her body's gotten used to the activity level she's at right now, and it's probably gonna take more to get the weight off.
- Cardio needs to be the primary weight loss tool, although a combination of cardio and resistance training is ideal. I would recommend 30-40 minutes five times a week if possible.
If she doesn't have time to get to the gym, then she should focus on cardio at home - walking, jogging, etc. If she cannot get to the gym, I would also recommend some push-ups, sit-ups, lunges, squats, and other exercises that do not require machines.
If she hasn't been dieting, then it won't take much to see some results. Starving is not the way to do it!
I would recommend starting by constructing a diet that is relatively SIMPLE. Keep it basic!! It makes it easier to follow. Don't worry so much about counting calories, and focus more on healthy food combinations at least for starters.
---6 or 7 small meals spaced out evenly throughout the day.
---Breakfast is a MUST. Breakfast jump starts the metabolism and gets the body burning calories early in the day. It would be a good idea to do some cardio before breakfast if possible.
---Proteins should be LEAN (chicken breast, turkey, egg whites, fish, occasional lean red meat)
---Carbs should be "good" carbs - NO refined sugar and minimize dairy (skim milk only) - stick with things like oatmeal and sweet potatoes or brown rice for complex carbs.
One or two servings of complex carbs per day (maybe three depending on how much activity she's doing), and then veggies can be eaten freely without any concern about quantity. Put the complex carbs early in the day, like breakfast and lunch.
---Stick to low cal sauces and salad dressings...avoid things like BBQ sauce or cream based dressings. Go for things like lemon juice, balsamic vinegar, and spices like Mrs. Dash.
---FATS should be "good" fats, and they are essential in the diet. Nuts, avocados, and omega egg yolks are all sources of healthy fats.
Here's a sample that you could use to modify based on her eating preferences and other lifestyle issues
She could do a meal replacement or protein shake for one of the meals later in the day if she wants to, but it should be a relatively clean protein, like whey or something without a ton of carbs in it.
1. Breakfast - 1/2 cup oatmeal and 4 or 5 eggwhites (one omega yolk would be fine too)
2. apple with 1 TBSP natural Peanut butter (peanuts should be the only ingredient)
3. Lunch - Chicken breast on salad with LF dressing (I usually use 1 tbsp LF dressing mixed with lemon juice and vinegar); 1/2 avocado can be added to the salad.
4. Tuna or other lean protein with 4 rice cakes and carrot/celery sticks (a small potatoe or 1 cup brown rice could be substituted for the rice cakes)
5. Dinner - chicken/fish with veggies (brocolli, asparagus, whatever); another option is an eggwhite omlette with veggies
6. Veggies as needed; raw almonds (a couple handfuls) or 1 Tbsp peanut butter
There are lots of ways to mix and match, but just try to stick to the basic elements of dieting...no sugar, minimal dairy, eat veggies whenever hungry, eat throughout the day, minimize carbs late in the day.
That's a good way to start, and then you can adjust the diet and training as necessary to get results.
Two other essential elements - PATIENCE and CONSISTENCY. Nothing happens overnight.