Mine just loves to poke her nose into everyone's business. She doesn't have a filter either, which seems to have worsened as she's aged. We popped around to my SiL's house tonight to drop off her birthday present, and my MiL was there, along with some people we don't know. She blurted out - so loudly, that everone stopped talking - "1001, has your sister still got her hemorrhoids?" So rude and inappropriate. I replied that I didn't know and gave her a bit of a look, but she didn't pick up on it and probed further (so to speak). She often does stuff like this - she can't stand not to be the one driving the conversation.
When my SiL opened her present, my MiL asked me where we'd got it from and how much it cost - so rude!