N.S.
L.,
Hi, My suggestion for your parties... have the parents bring goodies for the pre-school party, (you could have a sign up list) if they don't bring much don't wory. Have games and music going maybe some art activities. If the parents are invited to the party have the projects be ones they can help thier child with. If it's warm have a water balloon fight.
As for the birthday party's I would suggest combining them. I will be doing the same with my two girls who will be turning 3 and 1 next month. You could go to the dollar store for paper plates, cups, etc. Also you could have it at a time when it is not meal time that way you only have to have cake and ice cream. Hope this helps you!
N.