I know oct is far away,but I have a halloween bash for my kids every year. the venue is popular so I usually book around this time to make sure I have the space. My sister now has a son, and his bday is in Oct. She wants to do a costume party. She asked if we could do the parties together that way we could split the cost of the rental and everything else. I know this would help her if I split the cost with her. I was trying to figure out how to do the party without her feeling like it's not my nephews bday party. There will be about 30ppl there that I would invite and she would only have 8-10ppl. How would we word the invites or do we do seperate invites?