There's lots to agree with here, that others have written. Certainly, I hope you don't let your mother stop you from writing the book. As BethRags said, a good book is not written in a month, or a year, or even five years, sometimes. She need not even know what you are working on. If you do have it ready and want to publish, you then could easily take FluffyDinosaur's suggestion of using a pseudonym. Many many people do. There is nothing wrong with that, and it doesn't take away from sharing a story, educating, and fighting stigma.

I have been writing bits for a memoir for quite a long time. I shared a lot of very personal stuff on my blog, about my experiences. I'll admit that the disinhibition I felt when I shared it has faded. That is part of why my writing slowed to a snail's pace. But this is mostly because people who know me, personally, have access to my blog. My dad even shared my blog address around town. If I was totally anonymous, like I am here, I bet the slowdown may not have happened. I may have also included some stuff that I didn't, even while comparatively "disinhibited".