You were way more than gracious and giving in this situation. I'm sorry you're having to go through all of this w/ someone who is supposed to be
your friend. Friends care for and protect each other. At the very, very least - she should 100% understand why you wouldn't want to come to their house and/or ever be around their dog again. Instead, she continually baits you about it and makes light of it

. Dog bites can be very traumatic. It's not right that she seems to be bent on invalidating what her dog did to you.
You deserve better friends who treat you well and show you care and love.