I'm glad she made the transition into her new tank okay. She's probably just so excited that she has some new space to explore. In my experience, females are a lot more active than males, probably because they don't have to lug those heavy tails around.
Her darting behavior could be her just looking around or possibly, if she is doing it at the front of the tank and in one place, her "wiggle dance." Most bettas do a funny little wiggle when they see their owners and are happy.
I would only leave the salt in the tank with her for another day. Long term exposure to the salt can reduce its effectiveness if she gets sick and needs a salt treatment later. Your water parameters look good, too.
It sounds like your next plan of action is to watch her for a few days to make sure she settles in okay and then to just enjoy her and try not to get bit by the betta bug. Congratulations!