You were very respectful. You didn't grab her or demand that she cross the street with you even if she said no to wanting help.

Since you are asking for opinions: I feel it wasn’t wrong or right. You didn’t manhandle her or anything but she may have had a reason for not crossing yet. It may have also been a little confusing to hear someone stop park, get out of their car, and then come over. I would feel pretty pressured to follow along that person as well, not knowing what was going on or why someone was getting out of their car. But again you didn’t do anything wrong, I just don’t think you should make a practice out of this or think you were some kind of hero. Even if a blind person looks has a tent, they need to figure shit out for themselves in order to live in this world.

I think you did the right thing. As long as you didn't physically touch the individual without asking, it's pretty safe to say you behaved well. For my part, I'd like to say thank you for being thoughtful and for going out of your way to help another person.