Belinda has two daughters

[Bassim]

Have I made any mistakes?

Belinda has two daughters who she brought up on her own after her husband left her after a five-year marriage. She could never have managed without the help of her parents who took care of the children when Belinda was on night shift. But the most difficult and humiliating had been her contacts with different authorities to which she would turn for help, and who didn't see her as a human being but as an anonymous number they preferred not to deal with at all.

 

[Tarheel]

I would put a comma after parents. Also, try: various authorities she turned to for help. And perhaps: they regarded her as a nonentity--somebody whose feelings they didn't need to consider. Finally, consider: But the most difficult and humiliating thing was dealing with ....

 

[Tdol]

I would use the authorities.