What do I do if nobody RSVPed to my little sister’s party?

Hey, this is my first post on Reddit and probably my last, but I really need some advice.

For reasons I don’t want to explain, I have to take care of my younger siblings,my sister (8) and my brother (13). Things haven’t been easy, but this is the first time in years that I’ve actually had enough money to throw my little sister a birthday party.

I invited some kids from her class (15), but nobody has RSVPed. It's been 2 weeks. The party is coming up soon, and I don’t know what to do. I don’t want her to feel like no one cares or that she doesn’t have any friends. She’s been looking forward to this so much, and I don’t want to let her down after all that has happened.

Should I try reaching out to the parents again with new cards? Plan something different last minute? I just want to make sure she has a great day no matter what.

Any advice would mean a lot!