I'm a Pisces Sun too and I would guess that it's probably more a matter of timing. Especially if she recently got out of a 15 yr relationship. Also I think Pisces tend to be a little bit indecisive about things (at least I am lol).. so maybe she's trying to sort things out for herself before getting into another committed relationship.

Timing, and a matter of personal evolution. Someone with that much pisces, (depending on where in pisces), is likely to need a lot of evolution in order to monitor and maintain healthy boundaries, both in terms of expressing and defending their own limitations as well as in terms of protecting themself from others. And this sort of evolution can come in phases and cycles complete with regressions. In the mean time, pisces can either retreat or bleed emotionally, (ie, emotionally fuse), all over everything.

To many of us, that emotional bleeding feels really good. It can be strong, intense, and it provides the illusion of intimacy. It's not, though. And the problems that can result from emotional fusion are deep and nasty. Personally, I'd probably love being around this person too, but I'd also likely experience her as a sort of emotional tar baby.

You probably have some of the piscean tendency towards emotional bleeding too, which might make you seem like good partners overtly. But your cancer sun is likely to lead you more toward personal retreat as a stand in for good boundaries and your scorpio rising is more likely to lead you to both more intensity as well as a slight tendency to be vindictive as a way of creating space between the two of you.

My advice is to be absolutely sure you're both getting enough time apart, alone time, not just time with other people. And then to harp again and again and again about creating and maintaining healthy boundaries. Talk to your other friends, especially any who you think do well with their boundaries, and listen closely when they express doubt or hesitation about something in this relationship. They won't always be right, but they will have insights into where boundaries belong that you might not.