I am trying to find an アニメ I have watched a long time 前 and want to watch again but can't remember the name of.

This アニメ is about a common (i think 7-10) little girl who lives in a common village. And in her country there is a handsome prince that every girl is in 愛 with. She also wants to be with the prince too (obviously). But she knows she is too small to be with the prince. Then one night she sneaks in the 城 when there is a party. There she meets somebody (i think) and gives her the power to become older. Then afterwards in the 城 she meets the prince.
I can't remember anything after that.
Please help me find this anime! I would really appreciate it!
P.S. Some information may be wrong in a few places. Sorry it really was a long time ago! Also please insert an image if あなた can please! Thank あなた