Hi &
Mora! This can be tough. But you are so right. You need to be healthy for yourself & your granddaughter.
The first thing you could do is tell her what you're planning. You could enlist her help to either make less of the delicious (but unfortunately not terribly good for you) treats. You yourself could buy less of them, or give her her own "snack" drawer. One where you don't allow yourself to go. Out of sight out of mind!
A great thing to do is what you mentioned. Use leaner meats. Trim the fats off. And definitely grilling baking & slow cooking are MUCH better than frying. (I think that adding spices & low-calorie marinades makes them taste even better than frying!)
You could make a super healthy filling chili very easily. Just remember that there should be less meat & potatoes than there are chili beans onions peppers and the other good stuff ^^
For your dinners, do you add greens & salads to your meal? Baked chicken with stuffing & potatoes is very delicious sounding. And portioned out may not be so bad, but the best way to keep it portioned out is to fill up a little on non-starch vegetables & salads with light dressing/vinegar.
Don't worry too much about your granddaughter losing weight. Just explain that you want to eat healthier. Emphasize health. Adding more vegetables, subtracting the fatty meats... an excellent beginning. Your granddaughter may even feel healthier too! Vegetables & lean meats give better energy than do sweets & snacks ^^
We're all here to support you. You say you have about 100 lbs to go. Maybe you'd like to check out some threads on the 100 lb Forum:
http://www.3fatchicks.com/forum/forumdisplay.php?f=55
Or if you'd feel more comfortable with people who closer to your age, maybe the 50+ forum!
http://www.3fatchicks.com/forum/forumdisplay.php?f=217
If you'd like some recipes there are DEFINITELY recipe threads around...
For Vegetables:
http://www.3fatchicks.com/forum/showthread.php?t=126111
For Chicken:
http://www.3fatchicks.com/forum/showthread.php?t=123200
Best of luck to you Mora!!!!!!