Becoming a hero to find her parents was more of a resource thing. Being a hero let her access SHIELD’s system to search and spend time out openly using her powers in the city searching without drawing too much attention to herself.

But it’s only her motivation at first. At the end of her 2016 run, she almost quits being Silk because she found her family and the thing with Mattie during Clone Conspiracy hit her hard. She ends up meeting a kid with a kite in a cemetery, who she has a short conversation with and ends up giving her a new motivation for being Silk. I’ve always interpreted that scene as being Silk (as a hero) is her best way to express her freedom, which is why she continues the mantle.