When my girlfriend made a fortnite account I thought it was cool, but now I am thinking about deleting it.
Why would you delete it?
I think she's too addicted to it.
It is wrong to delete things that do not belong to you. If she ahs a problem you should talk to her about it and maybe get her professional help.
I'm doing it because she's cheating on me and I'm so over her.
It's horrible that she is cheating on you, but two wrong's don't make a right and you should instead just break up with her. Revenge would feel good, but also lower you to her level.