I'm so sorry to hear that you are in a similar position to myself....
My husband of 7 yrs seriously assaulted me last yr and I was admitted to hospital.
Assaulted me this yr in Jan. Difference this time was I called the police and he was arrested and charged, he is now on probabtion.
His mother and sister were present the day he attended court and heard my statement which was read out.
A day or so after that they saw the marks that he had left on my face. They really were not too bad but proof that I hadn't lied about what had happened the night of the assault.
To this day I don't think they believe me, even tho yrs ago my husband assaulted me in his mothers house shortly after she had gone to bed. How she didn't hear the shouting and crying I don't know, actually I do, she chose not to.
After the incident in January she didn't even call to ask if I was ok.
The point I'm trying to make is don't try to get support from your mil, she may never see the wrong that her son has done. I know mine certainly won't acknowledge it, not to me anyway. To do this would be admitting that had made mistakes as a parent and they are not likely to admit to that now are they. Instead get support from your family and friends.
Sorry for hijacking thread with my story.
Bit of a rushed reply also.....
Take care.