I'm really surprised that there are so many people saying birthday parties in June worked well for them! I'm a June baby, and it was terrible trying to get people to come to my birthday parties. In fact, after I was about 9 or so, my parent stopped trying, and I just had family parties from then on.
DeeTee, I'm glad you've got it worked out for this year. In coming years, I think a mid-January party would be fun, or a Valentine's Day party. The Easter celebration you have sounds great too!