So Update
Been just over a week since the incident. A couple days ago got pulled into the managers office about it (been waiting all week for this). The person who gave the milk went to management saying I had said all this awful stuff to and about her (I never directly engaged with her about it or said anything about her) She wrote this full statement about what had supposedly happend (I didn't read it but my manager told me about the key things I had supposedly said). She claims the person has been dealt with separately for giving the child milk. I was told I was not in trouble (the way she was talking I defo am though) but I don't think she believes me for the fact that I didn't say any of this other stuff.
The member of staff who gave the milk has decided to leave and not come back don't know if it was related to this or if they decided it just wasn't for them.