I'm probably the only fan in the universe that actually liked her and Quicksilver together.
What I enjoyed with them was that their problems felt more real (things like infidelity and emotional abandonment) as opposed to the problems most superhero couples face like time travel super villains and damsels in distress. To me, their real standout moment was when Pietro lost his powers and was about to kill himself (no thanks to your friendly neighborhood Spider-Man), and Crystal showed up to try and help him cope with his loss by bringing him to Attilan. Another plus was that we got to see them both as parents which is something superhero comics often ignore.