I did a 1200 calorie a day diet. I started it in April of 2002. I lost 35 pounds and have kept it off so far. I used [url]www.******.com[/url] to keep track of all the calories.
I ate whatever I wanted as long as I didn't go over 1200 in a day. That meant that sometimes, if I wanted something really calorie laden, I'd save up my daily calories just to have that one item. Not the healthiest choice, but I lost the weight nonetheless.

I didn't exercise.
The plan you've listed here sounds like a great plan. It looks like your basic diabetic persons diet, a proper balance of exercise and nutrition to keep you healthy and active.
I mentioned before using ******. If you do this diet, and I think you should, try using the ******. It will help you so much to keep track of your calories, nutrients, and exercise all in one easy place. It's free. I can't stress enough how this helped me keep track of my progress and continues to help me maintain.
I went from 156 to 121 pound. My goal was to hit 130. On ******, it shows your progress over time; here was mine.
April 5th -156
May 5th-147
June 5th-141
July 5th-136
August 5th-134
Sept 5th-130
I continued to eat 1200 calories a day but didn’t keep track anymore on ****** and by about February of 2003 I weighed 121, way below my goal. At that time, I started using ****** again and adding calories until I quit losing. I started eating 1300-1400 calories a day. I fluctuate between 121-123 on any given day. And remember, I don’t exercise. If you exercise regularly, you could eat more and still lose, or lose faster.
From time to time, I stop using ****** and try to “wing it.” Over time, I find myself eating more calories when I’m not paying attention, so I have to use it. It’s a small sacrifice of time for the benefits I’ve gained from being thinner.
Go for this diet. It sounds good to me. I think your mother can absolutely reach a 50-pound loss in 6 months. The weight will fly off at first. She could start out eating the 1500 for a month or so to get used to eating less, then move on down to 1400 and so on. The trick is, DO NOT CHEAT THE ******!

If you eat cake, make sure to mark it down, if you sneak a cookie in the kitchen or a handful of chips, MARK IT DOWN. The little “cheating” calories will blow the diet if you’re not careful.
Good luck