You can draw in the seal treasure 400 times (Which any sane person would never recommend) or you can get fragments from events. She will typically cost around 3k-5k from events, it's a lot however you'll get a lot of different items depending on the event. The events she is in will normally give you some points and you can get her without spending anything but that will take a few months.

Edit- She is no longer drawn after 400 pulls