Judy Blume, who has helped countless children deal with everyday problems and annoying little brothers, has been diagnosed with breast cancer. The disease caught her by surprise, she says, because she has always made an effort to live an extremely healthy life and cancer doesn’t run in her family.

Documenting her shock and the ensuing life changes on her blog today, Blume wrote:

Wait – me? There’s no breast cancer in my family (recent extensive genetic testing shows no genetic connection). I haven’t eaten red meat in more than 30 years. I’ve never smoked, I exercise every day, forget alcohol – it’s bad for my reflux – I’ve been the same weight my whole adult life. How is this possible? Well, guess what – it’s possible.

Blume underwent a mastectomy on one breast earlier this summer but, before that, she faced obligations–which required travel and being in large crowds of people–with bravery, keeping the knowledge of her illness to herself and relying on her family to help her stay strong. And, she says, she had a healthy support system in the form of other survivors, women she knew who had made it through the cancer and onto the other side.

As I’ve told my friends who’ve also been treated for breast cancer, I’ve joined The Club – not one I wanted to join or even thought I would ever be joining – but here I am. I’m part of this Sisterhood of the Traveling Breast Cells (apologies to Ann Brashares). Medical diagnoses can leave you feeling alone and scared. When it comes to breast cancer you’re not alone, and scary though it is, there’s a network of amazing women to help you through it.