I have found my daughter witha pill that she says she didnt need a prescription for but she doesnt remember what it is, please help me I'm concerned.

It is about 1cm and round it has 100 marked on one side and nothing but a score line for breaking it in half on the other. Oh and its white. she has another exactly the same but purple. Any ideas what they are she swears on her Grannys life she doesnt know what they are and I believe her as she loves her gran and would not swear on her life unless shes telling the truth.
I would be so gratefull for some ideas as to the identity of the pills please please please help!!!!

Hopefully soon