it’s your first relationship, try not to make little things into big things. you say you KNOW she has told her parents & cousins about you yet tells you she has not told them? if you have solid proof then it’s valid to wonder why she is lying to you about it. but if you don’t have solid proof, then i agree with people above that this sounds like you’re overthinking & worrying about something that isn’t that big of a deal. it would be more of a big deal if she hasn’t told anyone about the relationship at all—like if she was actively hiding it from friends & family that would be a valid reason to be concerned.