Weaning at 3 weeks

My current foster litter is 3 weeks (and 2 days) old. Their Mom is perfectly healthy, has plenty of milk, eats well, but isn't a very good mother. She is young and this is probably her first litter. The first week, everything was going well. For the last two weeks they haven't been gaining weight as well, constantly seem to be suckling each other or me, and whenever I put them near Mom, suckle happily and heartily until Mom moves. They have minor URI symptoms, but the biggest problem seems to be that Mom frequently gets up while they are nursing and doesn't seem to find them to nurse often enough. They defintiely seem hungry. Now that they are bigger, it has gotten better since they are only in a small area (my bathroom) and can find Mom when hungry. Of course it doesn't stop her from getting up, if she is hungry or bored, or looking for attention.

I have tried to supplement feed, but they don't like a bottle in their mouth. When I am there, they nurse from Mom better since I ensure they are near her. Since they are so into suckling anything, I tried giving them some of Mom's canned food. They were licking it, suckling it, eating it, and thoroughly enjoying it. I tried mixing it with KMR. If there is too much KMR they seemed to be aspirating it up their noses.

I usually don't start weaning until 4 weeks. Is 3 weeks too young? Does anyone have any better ideas for this situation with a poorly attentive mother, kittens not interested in commercial bottles?

Kittens can be weaned at three weeks, it just takes some patience. If they're not getting enough from mom and it's difficult to bottle-feed them, I'd say go for it. Better they grow up healthy than wait around for their mom to get her act together!

Yes its too early. You say you have the kittens in a bathroom. Is mom in there too and is she confined to the bathroom at all times? Personally I'd crate her and the kittens in a very large dog crate and don't let her out. You can put a small litter pan in there for her to use.

Maybe mom is being allowed too much freedom and that's why she doesn't seem to know to return?

Mom is with the kittens in the bathroom 24/7 and has been since they were born. Unfortunately, I don't have a crate large enough for the whole family to be comfortable, especially since the kittens are starting to wander. I usually have no problems leaving them all in a small bathroom. Mom has been sitting on the opposite side as the kittens. Now they can find her, but it doesn't stop her from standing in the middle of their meals if she is hungry or bored.

let her stand they will still nurse while she is like that. as long as they are gaining some weight and not lossing any that is fine. because they are starting to get around more they wont put the weight on as quickly. give it at least a few more days before weening starts.

Mushy stands too sometimes, and that doesn't seem to stop the kittens. They still find her and steal a meal lol. I also notice that Mushy nurses a lot during the night, so maybe they are nursing, just not when you see them.

3 weeks old is not too early to begin introducing the kittens to solid foods. If, as you say, they are interested in foods, then allow them to sample as much as they want. If the addition of the KMR is making it too soupy and they are getting it up their noses, reduce the amount of KMR you are adding. At this age, they do have little teeth and can easily break up any chunks in the food, however, I suggest a mushy pate-style kitten food for now. Also, Royal Canin makes a lovely first-stage kitten dry food called Babycat 34 (I think) and the little biscuits are small enough for little ones to handle. You might also give that a try as well.