How can I make myself look as unattractive as possible?

I'm really sorry if that sounds a bit weird or if I sound a bit weird. Let's just say my "friend" is looking to avoid something that rhymes with "smarranged smarriage". She wants to make herself look as physically unattractive as possible so no-one family in their right mind would want their son to be with her. She thinks of herself as fairly average anyway in terms of looks but she wants to take it to the next level. Many thanks and I hope everyone is okay.

(Also, my friend has tried talking to her family about her concerns and let's just say they were not very receptive.)