Purely theoretically, if a parent decided to invite the whole class so no one would be left out and got 15 yeses and 2 noes and then felt a bit poorly so booked an entertainer to help and then a few days before the party got 3 more yeses and then got a note from the entertainer about numbers (saying max 18) and considering there might be 2 more days for other last minute yeses from the 10 non replies left and
Party bags
Food
But
Great helpers, big enough hall
However
still not feeling great and GP sending for further tests
Would I they be unreasonable to cross fingers, make more party bags and hope for the best and not mention it to the entertainer beforehand