It is good that you are able to help out. I am sure your brother is overwhelmed as well. First of all the little ones need stability and boundaries, and most importantly love.
I would also suggest that they need to be in counseling right now, not if their dad divorces their mom. They are not stupid, they know things aren't normal and aren't right, but they don't have the skills they need to cope with them.
I would not try to take away Allie's blanket at all, nor would I make comments about her giving it up. It is literally her security and brings her comfort. And, she needs that right now.
I would suggest that you figure out how to get a table and chairs. I say this, because my kiddos who are all grown now, still talk about dinner at the table. For awhile we didn't have one, because our table wouldn't fit in the dining area. My kids really missed that. When we do family dinners now, they want to eat at the table. And, I can say, growing up we always ate together at the table and it was a time of bonding and sharing and we often spent hours at the table afterwards or on the front porch if the weather was nice. Kids need this and they need to see normal.
Allie may see you as usupring her mother's place, and no matter how dysfunctional a mother is, they are the mother. She may also be expecting you to "abandon" her as well, so they push it along, trying to make it happen by being unruly and rude, etc. Easier to push you away then for you to walk away. She's angry and confused and needs you to be there, unconditionally. Correct her yes, but don't let her see you disapprove. Does that make sense? Gotta love her no matter how badly she acts out. Find some way to bond with her, keep trying something will work.
I never worried about kids being in the fridge either and had a basket of snacks on the table that anyone could access at any time. I never did make separate dinners, if the kids didn't eat, they didn't eat. I suspect it is mostly a control battle at this point, not having anything to do with whether they like the food or not. Perhaps you could ask each one to pick out a meal, and no matter how odd it my sound go with it, sometimes the best meals are a hodgepodge. Can also try the brownie bite rule, you don't have to eat it all if you don't like it, but you do have to take a brownie bite -- because taste buds change :-) so something you don't like might become something you do like later.
Her roles are out of whack and she can't allow herself to be a child, until she knows the adults in her life can be adults.
I will keep you all in prayer. You can do this. And, those babies need you. Hugs, Lauren
You are right about Allie's blanket and bear. They are her security and she definately needs that right now.
I really feel that I was put into this situation to help me be a better person. This is all new to me too actually. When I divorced my husband, my daughter was 2 and a half. We didn't have any contact with him for three years due to his drug addictions. Then, I had to go along on his outings with Melinda until she was about 12. It was rough on me then as well but I only had one child to help get thru it, not three.
Allie loves making bracelets and necklaces so maybe I can use that as a way to reach out to her to bond with her. just thinking a bit here.