My daughter has 2GB of data per month - is it possible to stop her going over this through the Virgin settings?
Not possible I'm afraid. Some modern phones do have the ability to warn you and some will turn off mobile data when a pre-set level is reached.
I have a similar issue with this and my daugher - we did not have this problem with giffgaff but the only way I could do it was to ask Virgin to remove access to the data completely. Wish it was simpler. Also capping the credit limit on the account.