3rd birthday party and limited RSVPs

My daughter is turning 3 and really wanted a birthday party, so I planned her one and sent out the invites to all the children in her nursery class. I sent a message on our nursery app, the same way all the other invites we've received have been sent. Normally people get around 12 yes RSVPs within the day. It's been 3 days and I've had 5.

There is another party the day before, so I do get that not everyone will want to do both. But they could at least respond and say so.

If people at least were responding no, I could live with that. But there are 9 people who just haven't responded. And the real kicker is 6 of those people are regular party attendees and they are all going to the one the day before.

I just think it's so rude to not respond, and I also worry what I've done?? Why does everyone else get a response so quickly and I get so few?

There have been two parties in the same weekend before and it's been fine, people have responded and attended.

I'm worried I've committed some kind of social faux pas and have no idea what. And I'm just so upset for my daughter, who won't understand why her friends aren't there. Like all the people she talks about are the ones who haven't replied, including her absolute best friend she's obsessed with.

Maybe I'm over-reacting but my heart is literally breaking for her.

In normal circumstances, I'd be fine with 5 yesses, but because I know the kind of response everyone else has got before, I'm just so sad.

I am also 11 weeks pregnant, so my emotions may not be all that stable...!