Is being “secretive” rude?

For some context, I was visiting my family for thanksgiving and stepped outside (after dinner and all other guest had left) to talk to my friend who was dropping some things off for me, I also had some things for her.

I came back inside about 10 minutes later and got hounded with questions by my mother. “Who were you with?”, “What were you doing?”, & “Where did you go?“. I said outside with my friend because she had some items for me and left it at that, I didn’t feel the need to explain everything they got exchanged. Keep in mind I’m 30 and do not need to explain my life choices.

I told my mother I felt that her being so nosey was rude as she does it all the time. She told me I’m secretive and being secretive is rude.

So my question, is being secretive rude? Specifically when the information is none of the other persons business and does not involve them at all?

I realize I ‘could’ have told her what we were doing right down to the detail, but my mother is super nosey and is always butting into other peoples business for no good reason so I didn’t feel the need to share just to satisfy her need of being nosey.