Been a while since I read the novel but... I think the dad is foreign nobility, and his mom (grandma) was taken by Asher’s ancestor (forget who exactly), while taken touched some kinda special pond for royals that is responsible for giving the powers... or something. Powers only manifest in their time of need and in a form that you require, that’s why not everyone has and powers are different. Aria’s dad is still looking for them and the mom will end up with him. There’s also a judge character who is a dad side relative and finds Aria to look a lot like her brother.
