My MIL is a big fan of diets.

She's had a lot of success lately going gluten-free (she's feeling a lot better), and she's coming for a visit next week. I know that in general she's trying to eat fairly healthy (she's somewhat overweight and is working on it). Since her diet changes from time to time, I asked her what she was doing at the moment.
She said she's doing gluten-free, dairy free, and she's trying to go low sugar, low sodium, and low carb. Which is rather complicated, because a lot of low carb stuff has gluten, and a lot of gluten-free stuff might have lots of sodium or sugar, etc. So I can't just try to get some cookbooks at the library, and I'm not great at reading nutrition information because I don't know what all to look for.
Anybody have any ideas? She said that she doesn't expect me to try to make dinners for her, that she'd be happy to run out to the grocery store while she's here and get some stuff that she'll eat. She's a really sweet, wonderful woman, so I'm in no way freaking out over this. However, I'd really like to at least have some foods that she could munch on so that the grocery trip wasn't required the moment she got here, and also to be a good hostess. I'll probably try to get a nice selection of "munchie" veggies, like carrots (my 3-year-old is a carrot addict, anyway), celery, broccoli, etc. I don't know what "hummus" is, is that something that would fit that maybe I should get? Or pesto or something? I hear them talked about as health foods but I don't actually really know what their nutrition info is like.

Any other vegetables that are nice to munch on? We also have plenty of frozen veggies in the freezer (just veggies, no added butter or salt). We also keep a lot of fruit in the house, which tends to be my marker for when I have to go grocery shopping, because I have little kids who are fruit addicts. So we usually have strawberries, apples, grapes, and nectarines, at least. Sometimes blueberries, cherries, bananas, etc., depending on how much we can eat and what's on sale.
Basically, she doesn't want me to go to any trouble so isn't giving me many details, but I'd like to be a good hostess and at least have a few things on hand. So could use any ideas you have! We don't have a ton of fridge/freezer space (see the list of all the fruit!), although I might try to clean it out before her visit to make more room, so I'd like to use the room we have as well as possible.