You can leave her there if you want to. At that age though I used to stay at Hungry Jacks and sit away from the party with my other kids. With the play centre one I would pay for the other 2 kids and hang out with the parents while the party is on but buy food for the other 2. You don't have to RSVP about the other 2. Mind you, I live an hour away from these places, if I lived closer I would probably drop them off and leave.