Invites

Hi, i was wondering if you could help, I've invited my childhood friend to my big day. We don't really know each other anymore been awhile before we have seen each other. She asked if she could bring a plus one i agreed but now I'm wanting to give this space to a friend of mine who i am alot closer to. I have hinted by saying i need to know final numbers because they haven't got back to me about anything just that they are coming. What do i do ??