My partner opened 1S with a balanced 19 point hand. I had 16 points, 3 spades and 5 hearts and bid 2H showing a 5 card heart suit and 10+ points.
She gave it some thought and bid 3NT. As she knew that I had 10+ points I took her 3NT as a sign off in game with 15-16 points. At this point she knew we had at least 29 points. I could only count on us having 31 points and eventually passed. She doesn't play Gerber. What should I have done? She says that a rebid of 3NT shows 19 points, but is this true after a 2 level response by partner. If it is, how do you differentiate between 15-16, 17-18, and 19 after a 2H response?
BTW She made 6 NT.