I planned a princess party for my five year old niece.. I don't think I spent a thing... I just used stuff we already had...
I found the invitation wording online by searching for princess birthday invitation I think. and printed it up like an inviatation to a royal ball or soemthing.. and put it in pink envelopes leftover from something else.
I made hats out of paper and set them up on the table for all the girls to glue their own sequins glitter etc. on them... (first activity)
I made her a Hot Air Balloon Pinata out of a baloon and paper mache... and then attached a yogurt cup to the bottom for the basket...filled with candy..(second activity)
Then I sent them on a scavenger hunt for the Royal Nail polish... once they found it we painted their nails and you could get those toe seperators from the dollar tree (third activity)
I'm trying to think of the others.. but I do promise no money spent!! I had everything on hand in our craft box... was lucky..
If she is into this you could do a search..
Oh yeah.. we had left over beads.. so they all made their own bracelet..
then we didn't have to give favors because they all made their own for all the activities...
Oh I know.. another one we did... I had leftover soap that we bought at a craft store.. you melt it down and put it into a mold...
so I made them and then wraped them in pink celophane... and made stickers on the computer with the girl's names on them like princess Alexa.. and closed the celophane with the sticker..(one of their favors)
this was a few years ago... but it was so fun ... the girls had a blast....
good luck.. send me a message if you would like some more ideas