Is my mom being fair?

I am at home. I just went to the gym to be weights and plan on doing cardio shortly so I am still in a t shirt and yoga pants. In between I am going to run errands with my mom. She asked me to put on a skirt - she says she respects me and my choices but I should respect her and not wear pants in and out of her house. She says she accepts me for who I am and when people ask her what I am like she tells them that I am modern (as if there would be a point in misleading them) but it makes her uncomfortable. I can wear whatever i want (damn straight!) but she wants me to respect her wishes and not wear pants around her house. I told her it isn't an issue of respect but she said she thought long and hard about saying something. And now I am crying in my room. I'm not sure who is right. There probably isn't a right or wrong here. I haven't really been wearing pants around my dad because I know he doesn't like it (and even that I was starting to feel uncomfortable about- i think it is fine and I should be able to do it in front of hiim) but I thought my mom was OK with it. I thought she went it when she told me years ago that she would prefer that I was happy than religious. Well I'm not all that religious now and it feels right to me, it makes me happy. I shouldn't have to dress differently because I am running errands with my mom- or should I? Should I respect her comfort level and dress in a way that she deems appropriate when I am with her. I don't know why it should make a difference to her -I am my own person and represent myself and MY values. Walking around with me is not an endorsement of my point of view and even if it was- support me, the real me- the me I am finally comfortable being. Would she prefer I misrepresent myself? Years ago I told my aunt that i think my father would prefer a superficial relationship with me, he doens't want me to be honest with him and he doesn't want to know me. Even as I type this years later, I am tearing up and I realize how much it still hurts me. I guess I can't be told to dress differently and still feel accepted. Do I want to make my mom feel uncomfortable? But do I want to feel rejected- is that my problem? Is it my perception that needs to shift? So what if I wear jeans (not just mid workout yoga pants) to fly with my family today or run errands (my mom asked if I had a skirt to fly in- obviously it is much easier to fly in pants). What if I am out with my family at a restaurant in cargo pants? Why is that so terrible? I am not wearing pants to my cousin's wedding or shul or walking around in a tank top and hot pants. There is a girl who grew up in this community with parents like me and she too decided to wear pants and does it everywhere. Her parents adjusted. Would it be different if I were married? Would it be different if I were supporting myself? At this point it really makes me want to skip running errands with my mom- let her do it on her own or I will do it on my own. This isn't an issue of my best interest- it's not like weight or make up or anything like that where my mom can claim she is just worried about me (and even then ...) wearing pants will not adversely alter the course my life or limit my oppurtunities- there is no version of events in which that is true.
Stella asked me recently how things are going with my parents and I said "well". This isn't well to me.