We use an app called Spond to invite you to our events and allow you to let us know who will be coming. The email address you provide will be used to invite you to our group so please provide address for whoever deals with this kind of "family admin".
The more people you have to play with outside of our sessions the better so we definitely encourage multiple grown-ups per child or multiple children per grown-up. There's an open field for you to provide us details of everyone who will be coming, so you don't need to make multiple repetitive submissions. The children can also be added to the Spond group where we post photos from our sessions and useful recap content.