Mother in Law Can't Keep Her Mouth Shut

I am 32 weeks pregnant with my first baby. We told my mother in law that we were expecting around 8 weeks, but asked her not to share until we announced the news. We live in a small town, and found out that she stared telling people. My husband grew up here, and heard things through the grapevine.... I don't know any of these people (we moved to his hometown a year ago after his father passed away to take over his family farm), and it was so upsetting that strangers were finding out before I told some of my closest friends and family. My husband sort of shrugged it off like, that's just her, she's got a big mouth even though I was upset.... he understood why I was upset but really didn't think anything could be done. Fast forward to this weekend at my baby shower. My aunt overheard her sharing the names we have picked out (1 boy, 1 girl because we don't know the sex) with my friend's mother. I have only really shared the names with my mom and she has kept it to herself, and my MIL. If my MIL is telling someone she's met once or twice, I can only imagine who else she has told. I am so upset, and know I should talk to her about it directly, but she cannot take feedback or criticism like an adult. I've seen her in other situations completely shut down, and then shut out the person., even my husband who is her absolute favorite. We live on a farm and literally are next door to her - I get along well with her and need her in my life, especially at 7 months pregnant. I was venting about it to my husband tonight and it turned into a fight. He doesn't want to confront her because he thinks it will create unnecessary drama and I agree it probably won't do any good because she'll get defensive, cry, and not change... not to mention probably not speak to us for a few days or a week. But I still want him to talk to her so at least I know he supports me and she knows how upset we are. So I end up sobbing tonight and not able to sleep (thanks, pregnancy hormones!). I feel totally stuck. We can't say anything for fear of alienating her when we need her most, she totally plays the sympathy card because of being so recently widowed (for which I do have sympathy but it doesn't excuse her lack of boundaries). I obviously will have to stop sharing things with her that I don't want the whole town to know, and now my husband is asleep and I'm awake and crying. I know it sounds dramatic to be so upset, it's in part because of the pregnancy. I just needed to let this out, and see if anyone else has experienced similar issues. How have you/would you handle this? She does a lot for us and I get along well with her normally, so cutting her out isn't an option. I don't want to have to keep things from her when I am able to share them with my parents. Part of the joy of this experience is sharing things with family but she obviously isn't trustworthy. I just feel like she's so disrespectful when we ask her not to share things and she blatantly does it anyway. I am at a loss. 😢