Contrary to popular belief you can start civil action against a person from birth, up to age 18 they will need a next or litigation friend, who is often a parent. The age of 10 is when you lose immunity from criminal prosecution, you may find Walters v Lunt 1951 of interest.
As with any Civil action first ensures the family are able to pay before starting action and try to recover the cost of repair without court action if possible, court action should be the last resort.