Mr Stroodle, glad to hear things are moving along and it's relatively straightforward with no children involved. But I still want to issue a note of caution.
a) she might do a 180 degree shift if things go south in her romantic life and she doesn't have a girlfriend who will look after her.
b) she might be hoping that you will continue to be her best friend and be generous with her in the financial separation.
my advice is to hold hard to the notion that before a friendship can be established, the marriage needs to be dissolved. ie listen to what your lawyer says is a fair split and stick to it. If she really is a good friend that should be okay with her, shouldn't it?
Best friends, it turns out, can often turn out to be someone wanting to put you in the position that you will always be wanting to please them.