DENIAL!!!!! ADHD *EDIT*

My step daughter is 8 9 in feb. She has been diagnosed with ADHD. My husband her father is in denial about the diagnoses as well as my inlaws. We have tried therapy changing her diet. Nothing is working. Today I had her physical and I told her Dr her Dr wants to try meds for the new school year. I am all for it as we have exhausted every other outlet. I legally hold no rights to her. I do have permission to accept or deny treatment for her at this one clinic.

I have no support in getting her treated!! I believe my marriage will end if I go behind his back and Medicate her (accept the treatment). I have no clue what to do.

She was already "THAT" kid at her old school she will be going to a new one now. I don't want her to be that kid again.

Please some advice.

She has become violent at school previously. The tantrums are ridiculous. She can not sit still with out fidgeting and almost crawling out of her skin

EDIT* I have not made her that girl everyone at school thinks of her like that. Kids literally hates being paired with her! She would come home and tell us!!

So what should I do stand by and watch her struggle?? She is beyond bright.