E.S.
For my twin sons 1st bday we did a football party and had everyone wear something from their favorite teams and we had the twins in their jerseys (I'm a Steeler's fan so one was in a Steeler's jersey and my husband is a Falcon's fan so one was in a Falcon's jersey) and we did the whole house in football stuff. Since they were so young and since we mainly had our friends and family there, not that many kids, we couldn't play games or anything. I think just by them being the bday boys, they were the center of attention by themselves. We had 1st bday bibs on them and that helped them stand out some. I would maybe do a princess type of party and have her in a gorgeous dress with a tiara that has a 1 on it or something. Check party city or online for ideas.
Also, if you have a Giant or a Wal-Mart near you they give free 1st bday cakes that are small for the birthday girl to dig into. We had to get 2 because we had 2 babies and Giant was so accommodating and our cake was great (we did a football field with the Steelers on one side and the Falcons on the other). I hope this helped some, please let me know how things go.