C.M.
J.,
Sounds like you need a mom-of-the-year award. I'm sure you're doing a great job!! Wow!! You have your hands full. But take care, things will straighten out.
As for your 2 year old eating machine . . . try putting out small, healthy snacks for her to munch on. Put them in places she can reach, where she can easily access them. She'll be more apt to "eat" something that tastes good than something just to chew on. She's also probably teething. Another answer may be that she's nervous, she's anxious about things. As you've said, you're home life has been turned upside down. (I pray your husband recovers). As a mom of 6, I've often found that in order to change a behavior, I needed to replace it with a positive behavior. When you take something away from her that's been in her mouth, replace it with a toy (while discouraging her from "eating" it) or something that's good to eat.
As for the potty training, leave it be for awhile. Like you said, your routine is just getting back to normal. Everyone is adjusting. Potty training will happen. But the more you push it, the more you fight, the less likely she's going to go along. I also have 3 (out of 6) children with ADHD, and associated disorders. They can be a handful just by themselves. But your son sounds like he's doing wonderfully!! And so will your daughter. Take one day at a time, your timetable for potty training is your own, not what society says it should be.
I applaud you for the wonderful wife & mother you are!!!
C. M