UNLESS you BF is a professional, you should have NO ONE ELSE teach you! I had a buddy of mine teach me that was a single digit handicapper, and when I decided I wanted to get a little more serious about my game a take some lessons.....I had be UNTAUGHT my bad habits....it was time consuming and expensive.
I don't think Sandra is looking to become a professional. Anyone that knows the game can introduce someone to it. The BF can show her the basics. If she likes it that much afterwards and wants to "take it to the next level", she can always visit a Pro.