we did a first birthday party (which in retrospect was more for us than the kids)

DD had a 5th party and we were living with my parents while building so we had it at a playcafe. DD2's birthday is 11 days later so we had a combined party as neither child had enough friends to fulfill the minimum number.

Otherwise we tend to have a nice dinner and a cake with the grandparents on the actual birthday.

We are planning on having alternate birthday parties for dd1 and dd2 for a while and then work out what to do for dd3 as she gets older. For the child not having a 'party' I think I might do a playdate birthday with 1 or 2 close friends with a few small plates of party food and no structured games etc. Less stress, tidying before
and after too.

Socially I think birthday parties have more meaning for children as they get older and start developing long term friendships with school mates, JMO but if I was going to do one while at kindy or one when they start school I would wait until they are at school