Hi CW,
The advice from your DB coach makes sense to me. I don't see any harm in making an anonymous call. And, I think bringing this up to your H in the way suggested would be good. The A coming out in the open affects you too! Believe me, I know how stressful that is, and you have the right to speak up about that. This is YOUR M, not hers!
Pluck up some courage and speak up, my friend!