Can mail be forwarded to a former employee that no longer works at a job setting?

I'm writing a letter to a head teacher at a school in Argentina, but found out she no longer works there. She left her job in 2014, so it wasn't too long ago. Will the faculty at the school forward it to her home address or new work address? Can mail services still get it to her even though it's mailed to her former work address. Unfortunately, I don't know her new address, but only know what school she was working at. I'm writing her an admiration letter, so I want it to reach her.