My teen girlfriends mom is putting a strain on our relationship..help?

[michael h]

My girlfriend is 16 and I'm 18. We've been dating for 6 months on Monday. And she's thinking of ending the relationship. She's open with me and has told me that it isn't me it's her mother. She still loves me and I still love her. The problem is that our relationship has put a strain on her and her mothers relationship and she wants to gain her mothers trust back. The reason this whole thing started is because her mother found out we were having sex. And shes willing to leave me in order to fix her relationship with her mother. I want to set up a conversation with her mother face to face to apologize and try to work out the issues. I need advice on what to say and how to say it. Thanks alot for your help