He/she who pays is entitled (IMHO) to ensure value for money. If the child cannot be trusted, and this one clearly cannot be, then the parent has a duty to do what is best for them.
That said I didn't go to Uni but my understanding is that it is not like school where you attend lessons all day 9 to 4 but are in fact left pretty much to choose which lectures to attend and when/what to study. It does seem that "Mum" has rather got the wrong end of the stick here.