If a girl who is the age of eighteen wants to get marriage and never get married before does she necessarily need a Wali?
If yes what are the requirements does she need to make the marriage valid?
A girl at age 18, does not necessarily need a Wali to get married. However, marriage through the media of the Wali is the best for her, even though it is not essential for the validity of her marriage. For the validity of her marriage, the girl needs to clearly state her acceptance in front of two Muslim male witnesses. The Mahr is upon the boy, and he will have to give it to the girl upon marriage.
And Allah knows best,
Mufti Waseem Khan