Hi, thank you for your question. Just a bit more information required to fully assist you:
-Is the father named on the birth certificate?
-Have there been any agreements regarding arrangements?
-How often has he done this?
My name is ***** ***** I have been a solicitor for more than 35 years.
Since her father has Parental Responsibility for the child then he could collect the child from school - but he has no right to remove her when she is with her mother.
If he does remove her from school - or fails to return her after contact - your daughter could make an Urgent applictaion to the court for the return of the child to her care which would be granted.
She could then go on and apply for a Child Arrangement Order confirming that the child lives with her - and a Prohibited Steps Order preventing him from removing her from her mother's care
Your daughter should offer to discuss matters with her ex using Family mediation
to agree a Parenting Plan.
She can read more here
I hope that this is of assistance - please ask if you need further details