Well, she only lodges there and the character is at least 17 (possibly 18?). Not sure what legalities apply here... but it is a stupid threat to carry out, because the other two girls will be greatly saddened and wear them down to take her back. And surely it only adds to the dreaded 'stress' on Sophie which Michael seems otherwise eager to avoid...
Thanks but she is still at school so I say she is sitll a minor.
I must say that I really do find Pippa to be an unlikeable character and Michael is even more unlikeable.