She is 22. I felt very bad. Please help me.
It's none of your business and it's her choice what she does.
Where is my invite?
Get her to give me a DM.
Grow up, OP. She's an adult.
At this very moment? I mean you could always burst in and shout "it's a prank!".
Have a foursome so she gets jealous.
Inform other members of the male extended family/community and consider the next step. You can give all the guidance in the world but if they wont stick to the value system you have to make a physical intervention.