Separation anxiety

Sparklefizz I think that makes it worse as she ll scream anyway when the time comes for mum to go
They do get used to it and it will be so good for her to realise mum can go away and come back The nursery will be well used to dealing with babies toddlers and even older children with separation anxiety all the best to deal with it when young
Don’t let her see your anxiety or your daughters it will transfer like a rash

Can the baby's Mum not stay with her for a while each time until she settles in?

annodomini
The OP said that the baby is one year old.

My GD has just started nursery at a similar age - just turned 1 yr. She too liked to be around her Mum & over the last year will tolerate me too now.
Nurseries usually have 'Settling In days' - where the go for a short while. This worked well for DD & DGd.
DD was surprised how quickly the change was accepted. Nursery staff are experienced in separation & reassure both parents & children.

You haven't said how old this baby is. If she is of an age to learn to socialise with other children, it would make sense for her mum to spend some time with her at nursery, gradually taking time out to allow the child to mix with others.