She had 2 x-chromosomes.
My son used to do youth ministry. One day a girl (but dressed like a boy, etc.) asked him if she could join the boy’s night at church. He replied “Sure - as long as you have an X and a Y chromosome!”
He then went to the pastor to tell him of the request and his response. Weeks passed and the church leadership determined that they shouldn’t exclude people from activities due to their “gender” and that she (and others) would be allowed to attend boy’s night.
My son never did separate events for the kids based on sex after that.