3♥ is IMO a horrible underbid by North.
- Think North should bid 4♦ with stiff & 4+ cd support.
- Think 3♥ should be limited to 3-4 cd support, 12-13 total points, 12-15 is too wide IMO, 3♥ should be 12-13 catering to blah AQxxx Jxx Kx Qxx type of hands that don't want to be in game opposite min 2♥ bid and just respecting partner's force and showing fit. It has to bid 4♣/4♦ (spl) /4♥ (14-16/17 total point, no spl?) /3♦ with better hands.