You definitely do not have to have a birthday party for a two year old.  They will not remember it so it would certainly not be for them.  Four presents is more than enough.  I would definitely not do 15 especially since it sounds like you have an older child.  You do 15 presents at two where will you be when they are 12?  Besides 2 year olds care more about your presence than presents.  Celebrate by making it their special day with time and attention together as a family.  Do fun things together.  Make it memorable by making it a fun time with the people she loves most - her immediate family. 

Hi,

No they don't have to necessarily have to have to party, that's up to you.  I've had one for both my boys, but it was just with family.  It wasn't until my oldest turned 4 that I had a friends party for him, as I felt that was a good age to start as he kinda got the whole thing.

If  you have heaps of ideas for presents (sorry don't have girls so can't really give ideas) maybe tell other family members your ideas and they can get some aswell....  But I love the maxim that you have to get the presents by it's great.  Hope some of the other mums can give you a must have item (if there is one)  I'm not really sure.

Good luck.