Blind people have a responsibility to accept all help offered

I get on the tube with 3 or 4 of my close friends. It’s quite a full train so we hold onto the pole in the middle and I let my cane dangle from the elastic around my wrist. We’re having a nice chat about which market we should go to next when a lady sat in a priority seat offers to move for me.

I say thank you, but no, it wouldn’t be necessary, we weren’t on the train for long.
She stood up and moved anyway, then proceeded to look at me.

My friend suggests I should just sit down because it was nice of her.

But how is it nice to completely ignore the words that leave my mouth? Why did this random stranger, and more painfully, my friend, not trust me to know my own capabilities?

I’m sure the lady felt fantastic for her good deed for the day, but I just felt small, pitied and misunderstood. My friend should have stood up for me. My eyes function differently, but my legs are fine.