I'm quite a private person with regards to personal life, alwats felt uncomfortable talking about achievement (could be regarded as boasting) or events/happenings. Mom, however has no filter on what us appropriate to share with people
FFor example, I lost a family member in quite unsettling circumstances last month, told only my closest friend. No one else. 4 school moms (not really friends) came up to me in the playground a few days after his death and offered condolences. It appears that she stood there in the playground on her day to collect the DC and told a group of people. Now, I'm not one to judge on how people grieve, but it upset me greatly, that people who I chat about the weather with at most, know this business because she just won't stop blurting to everyone. 
This morning it's come to a head as it's report season. She want a photocopy of all their reports and cerficates. I know this means she'll be flashing them around at all the various groups she participates in. I'm uncomfortable with thus as DH and I tell no one, apart from in the vaguest terms "yup, they're doing fine, and enjoying school" if asked directly. She's had a massive huff as I've kindly decline to photocopy the stuff and taken away her boasting evidence. I've been made to feel the bad guyion this. And I don't really think I should be made to feel that I am in the wrong.
Does anyone have advice on how to deal with this? I have a feeling that my reticence h arisen from the many moments in the past where her insensitive splurging of info has made me (and others) uncomfortable.
Sorry for the essay.