My relationship what should me and my gf do?

her mom came in and note this is the 2nd time this occured, first of all she is 21 and i am 23 her mother came in her bedroom tonight and said after 5k lets go guy browsing and i want you to keep your mind open and not be dead set on this guy. it really upset me for what she told her and my gf said are you joking she said sort of, then my gf got defenseful. i dont get why she is like this. what should we do? please help!!! she tries to control her relationship and she has guardianship on my gf. help me.