MIL problems

So we leave with my inlaws because we are indians and that is our culture.The problem is that my mother in law self invites herself in our couple only day outs.We both work 5 days a week and I work on a saturday as well so sunday is the only day we get to spend some alone time together by going out driving around or shopping and having lunch.But last night this woman very sweetly asked me what are my plans for tomorrow being it a sunday I said we will go to the mall for shopping and she is like ok m coming as well.Fuck her bitch I didn’t get my legs waxed to wear a dress after such along time to go out with her😡😡I wanted to look good for my husband because he likes me dressing up.I told my husband that I didn’t like the idea of her coming with us but we don’t wanna sound rude to her as well😔Moving out of the house is not an option because it will be considered unrespectful😒Please ladies any advice on how I can or we can very kindly tell her that we need our our space and free time as a couple and that she is not invited with us anymore....