I'm assuming with low to no carb, she isn't really trying to get any muscle, but does she know that gaining muscle would help with burning fat more than cardio. Cardio burns fat at the time, muscle will help burn fat all day - always a plus.
When I'm leaning, I like to eat these types of meals:
Shrimp with greens, usually something in the package, I don't care, as long as it is green (green beams, broc., peas, yada, yada).
Scrambled eggs (5-6) with either tuna or shrimp in it, minus the egg whites, except I add one whole egg with anything green or carrotts. Mmm, I looOOOVE carrotts
Tilapia (fry them with Pam, spray with fat-free butter, top with Frank's Red Hot), with carrotts or anything green.
I'll buy the 98% fat free turkey and eat 4-5 slices with carrotts, tomatoes, mushrooms, or anything green.
I'll mix the veggies with each. When I'm doing carbs, I do corn tortillas or jasmine rice.
As far as water intake, AT LEAST 1 gallon a day. I'm not sure what other people do, I think it's like 64 ounces or something. If I do eat something out of the can, like tuna or something, I'll add more water in because of the sodium.