Well, I have only raised one also, but we put them in separate but joining paddocks to wean. They could see and sniff noses, but the baby could not nurse through the fence. We had them separate for 4 months and tried to put them back together. Baby started nursing again and mom let her, so pretty soon we were back to square one! Just my lone little experience, I am sure there are experienced breeders that can give you more info!
Holding at 4 horses:
22 yr old grey Arab gelding,
3 year old grade buckskin gelding,
5 1/2 month bay roan AQHA gelding
5 month old AQHA palomino filly!