I overall liked this book and found it both funny and sad. 
Having a 102 years old Grandma arrested allow for a few comics situation, it's not like threatening her to spend the rest of her life in prison has any effect, her life is already long enough. 

My main negative feedback is about the hypersexualisation of the main character, with graphic details. The same goal could have been achieved without that much details. This is neither innovative nor subversive. It was done way to often in all medias across the century, especially for women written by men. Nowadays, it just feels redundant, and kinda creepy.