Well, if you've been friends before, and now you're interested in her in another fashion, it
would feel different when you're talking to her. If she's giving off signals like a more personal relationship would be welcome, go for it. If she's not at that point yet, then keep being your normal self... or the one closest to the one she remembers. We all change with time, so she'll probably be cool with that.
Take your time, test the waters, and see where things go. Slight nudges are okay, but pushing for anything at a time when she's facing a battle like this would be a bad idea, methinks. Just be a friends for now, help her get through it and try to relax into the situation.
This is through the benefit of 60 years on this planet, m'dear... hopefully younger people might have other takes on it!
~~me~~