Can possesive, controlling, jealous, suspicious people change?

I am on a break with my gf. She really loves me and I and i love her. But i was suffocating with her controlling, jealous, possesive, suspicious, interrogative character. In moments of honesty she accepts it. We can be together only if she changes that stuff, otherwise we will be in a miserable relationship. The question is can she really change and how?