So, four problem cows. Let's see.
Two with twins. Did they at least accept one calf? If so, I wouldn't worry so much about it. I'd be really worried if a cow had twins and abandoned both. Some cows just don't get it when two calves show up. If one does it to us, unless she calved in the yard where we can monitor it, we just take the rejected calf and put it on a bottle. If someone else should lose a calf, then we do an adoption. If a cow calves early enough in the season that the barn is an option we will just put the three of them in a pen and leave them there until she darn well takes them both. Once the calves get to a certain size, the cows opinion of it becomes a lot less important. That calf will find a way! :wink:
As for the lame cow, it could be that she just didn't feel up to the job once the calf was born. If the cow doesn't stimulate the calf and give it a good loving when it's born, the calf doesn't bond either.
Then comes the cow with the bad udder. It could be that the calf just couldn't handle it for that important first suck. Then it gives up and quits trying, and it's a slippery slope to losing interest in each other after that. This would be another cow you'd want not to calf in the pasture. We've milked and babied and helped pairs like this in the past, and once the udder gets over it's first big after calving spell, the size comes down to where it can be managed. If it happens in the pasture, though that's another story. If a bad uddered cow calves in the pasture here, and the calf can't handle it, then the cow goes down the road.
We've had all these problems ourselves. I don't think you've got a big problem here. Just four cows who managed to time it so it seems like one.