What would DD like to do? DS1 was adamant that he wanted a 4th birthday party at soft play, so thats what were doing. If your DD wants something that is appropriate to invite the whole class, do so but expect many to be away. If she wants to do something special with one or 2 friends - visit a local attraction like an aquarium, do that with her close friends.
It is the etiquette at DS's school to invite the whole class to the party. As DS's birthday is in the summer holidays, we invited the whole class last year but less than half turned up. It was a shame really as we'd gone to a lot of effort to hire a hall and an entertainer etc and it was wasted on so few kids.
So do I bring the party forwards to the school term and invite the whole class or leave it where it is and just invite DS's friends but break the 'etiquette'?