my daughter is the organizer and no longer has an iphone. how do i switch organizer to me

She would need to disband the Family Sharing group entirely, and you would need to create a new one. You can on your own leave the current Family Group and create a new one, you don't need to wait for her to disband the existing one. But she won't be able to join a new Family Group if she doesn't leave the one she is currently in.

Link-> Leave Family Sharing - Apple Support