So, my friend's new donkey finally had her baby last weekend, a little girl. Mom and baby are doing well, but owner is very inexperienced

and has a few questions:
1. is it normal for the mother to have a small udder? (I haven't seen it, or have pics yet). The udder does seem soft.
2. The vet reduced the grain, donkey mom got bitchy, owner increased grain, donkey is happier. Is there a recommended/safe grain mix for new mom donkeys?
3. The vet (a horse vet) told the owner to wean the baby at 4 months. Other sources tell the owner to wait to as old as 9 months. Is there a norm?