EU family member AFTER break down of family

[Ubisiko]

Hi, I am looking for some advice.

My mom, my brother and I came to England around 2015 after using the surinder singh method so we got a residence card that is valid for 5 years as a EU family member . The thing is that my mom, who was married with a British citizen got divorce and the "eu family" got dissolved.

I am not worried about her at the moment, as she was married for 3 years and was living with his ex partner and her application is being made at the moment through a lawyer, but I am worried about myself and my brother. We applied as a dependant of my mom's ex partner but now that he is not part of our family, I don't know where we stand ? Our residence card is valid until 2020 .

Our lawyer told us that is possi me to applied as a dependant of our mom after she gets the right to remain but I am in a full time work and the same goes for my brother. All the bills are under my moms name , and be still live in the same house, but I just wanted to know if there's other way to approach this situation.

Thanks