Hi. My name is Irasema also!!!! I am Puerto Rican and was named for my mother childhood best friend. I had found a website which indicated the name was actually two names put together. First being
IRA which has been found in Hebrew and Hindu. It means watchful or decendant. Second being SEMA from Greek for divine omen. I can't locate that particular website right now, but I have found both names listed on the following site:
http://www.babynamesworld.com/meanings-of-names.html
If anyone can locate more information, I'm always interested.