Overall, I always saw her as fairly strong. The scenes that are most vivid in my mind are the ones from the 1968 arc when she would face Nicholas or Cassandra with total equanimity. The scenes toward the end of that SL with Nicholas in particular, you knew she was one tough broad.
For whatever reason, though, whenever Barnabas was involved, she turned into complete j-ello. Even when his plans were totally insane, when there were other more reasonable and more rational courses of action, yeah, she'd register a protest, but 9 times out of 10, she'd cave like a house of cards during an earthquake. I think it would have made for a better story if she had been written as a strong woman consistently, but she wasn't.
So doormat with Barnabas, strong with everybody else.