moh dilemma

The friend I wanted to ask to be my MOH, I have only known her a few years. But since getting engaged, she has been so excited and wanting to be involved. She buys things and is wanting to plan parties, but part of me wonders if she is wanting to become so involved because she is convinced she won’t get married. My partner jokes saying the 3 of us are getting married. Has anybody else had this type of situation?