Am I overestimating my relationship with my mother in law?

We occasionally have really good conversations and have gotten to know each other well. Well recently she knows me and my husband (her son) have been having a few issues.

She’s told me that he shouldn’t be going out to the clubs without me. And I tell her “well if he goes out, I’m going to go out with my girl friends. Simple” And she proceeded to tell me that that’s not right, that women shouldn’t be going out, and I shouldn’t be going out just because he’s out. This makes me feel bad because if he does something why can’t i? Maybe I’ve overestimated our relationship and maybe I shouldn’t tell her everything…. I don’t want her to view me differently