Hi! My mom used to watch a japanese cartoon which, in Spanish, the main character was named "Zafiro" (Sapphire), and she was a princess who was made to live as a boy so she could be the heir of the throne. So she was made to do all sorts of prince stuff. That is all she can tell me. Thanks in advance!

Run a search on Wikipedia for "Princess Knight".
(excerpt) Princess Knight is a Japanese manga that ran through four serializations from 1954 to 1968, as well as a 1967 Japanese children's animated series. It was dubbed into English and brought over to Western audiences in 1970, where it was called Choppy and the Princess.

Thanks a LOT ThatDaveGuy!