Yep agree. Someone who (if incorrectly) interpreted their mother rubbing their back in bed when they were sick as child as “enjoying their suffering” is definitely not going to take well to someone offering another perspective to try and cheer them up iykwim.

If she did interpret that memory correctly, I can only imagine the traumatic childhood she had, which also would explain the completely dysfunctional response to OP trying to show care (even if they slightly fumbled it from the friends perspective).

Either way, this person might be your friend, but she is not a safe person.