How to announce pregnancy to in-laws

My MIL is SO DRAMATIC. My husband and I have been married for several years and we live 2 hours away from them. Sometimes when we go visit she cries and clings to him like he's been off to war for years or something. It's awkward for everyone and he hates it. We have debated over how to announce our pregnancy because she is so selfish and likes to be the center of attention. Ideally, we would have liked to announce on Mother's Day but even my husband made the comment that she may feel like we took over HER day. My question is, given her flair for the dramatic and potential for this announcement to get very awkward and potentially hurtful (depending on her response) is it appropriate to have my husband tell his parents over the phone?