It could be that she isn't getting enough from the baby bottle nipple, if they are having to much trouble they will give up, it's possible that is what's happening. I would cut the opening bigger and feed her more often, this is especially important if she was just pulled from her mom (I will not sell a kid off it's mom after a week old, it's way to stressful for kid and mom (it's going to be stressful for mom anyway))(actually I won't sell an unweaned kid that isn't already nursing well on the bottle). It can be hard to tell if there is enough milk coming out of the nipple, even though you can squirt it out does not mean she's getting it out. Pritchard nipples are good, I'd get one of those!
I wean sell kids off at 10-12 weeks old, but keepers I keep on longer. Yes a kid will survive being weaned earlier, but that doesn't mean it's good for them. The absolute earliest a kid should be weaned is 8 weeks, and the only time I do that is for a buckling that is staying intact and acting alittle too mature! For keeper doelings and bottle kids they stay on the bottle (or on mom) until they are 3-4 months old, it depends on the kid, I wait til they are 'ready' before I start weaning (for the bottle kids, I usually just pull dam raised kids when I'm ready).
You've heard about bratty bottle raised goats? It is my theory that that comes partial from kids being weaned to early, my kids that are weaned at the proper time will NOT take a bottle after a month or so after being weaned. I have one goat that will suck a bottle, to the point that I couldn't give one to her kids w/ her there, I did not raise her but I'm guessing she was a bottle baby weaned to early. I have another one that was not a bottle baby that likes the milk, she won't nurse off the bottle, but she will try to bite the nipple off to get to it.
