Princess Themed Birthday party..turning 3:-)

Cute idea! FIrst... if you aren't inviting the whole class, be careful about exchanging info via cubby. Talk with the teacher about how you can get the other parents' contact info and go from there.

At this age, keep it very short and sweet. You could do a tea party and invite each girl to come dressed in her very favorite dress and greet each one at the door with a little crown. You should be in a dress and crown too and I would have dad there as the "King of the House"- complete with a crown and robe.

I would do a party that is either mid-morning or late afternoon and have tons of petit fours, mini cupcakes, tea (warm) and sparkling juice. You could either do this at your apartment, setting the dining room table or call around to local restaurants and see if they could put something together for you. Tea and desserts for 5 girls and 5 moms shouldn't be too pricey!

Yes the King (dad) should attend his princess's party. Suggest the girls come in their "royal attire" but maybe have some dress up items available to help them just in case.

Just an idea-- are you providing princess dresses for everyone? Because some kids don't have those sorts of 'extras' around, or may not be able to afford it.

Here's an idea for a twist on your suggestion: Elisa Kleven has a very sweet book called "The Paper Princess", wherein a paper doll a little girl makes takes off on her own adventures. You might consider doing some sort of paper doll activity with markers, glue sticks, sequins and other trimmings handy. If you have a doll for each child to decorate as they wish and two dresses, it's a great way to get a party started and each child already has their 'goody' of their own paper princess. The story is the entertainment, parents don't have to worry about dresses, etc. This way, you have activities, most of which are sit-down and perfect for a small space. Keep the activity simple too, as most little one's fine motor skills aren't overly developed.

If it were me, I'd try to have a birthday that is very simple and requires nothing from the other parents other than showing up/dropping off. I think an invitation in the child's cubby is right, unless there are other kids/parents who will be offended. Then, perhaps you could ask your child's teacher to use a little discretion and ask her advice.

And know that kids this age have some big emotional reactions to birthdays/birthday parties, so if you have a crown for the birthday girl, have one for the others. No one likes to be 'less special' and youngsters at this age have a hard time containing those emotions. (This is my preschool-teacher self talking here!)

And yes, have Daddy attend. You'll want extra hands around with 5 three year olds!

I love Princess parties.
I wouldn't buy the costumes because if I was a guest I would love to dress up my princess. Since it is only 5 kids maybe a friend or family can allow you to have the party in their house, If not maybe a family friendly restaurant. I don't know if any movie theater is still playing Tangled or any Disney movie but if they are you could also have the party there and then the girls could watch the movie (but then again my girl is almost 3 and I doubt she would stay still the whole movie, but would be nice to watch a princess movie at the end of the party).
They can make their own crown, and jewlery!
Yes, ask for e-mail or phone and write "please let me know if you will be able to attend" or RSVP or something like that (I forgot what it is, sorry) even so, many moms don't do it even if you ask for (grrrrr!).