What's the Name of That Book??? discussion

I read a book a few years ago (maybe 2009-2012?) about a family that was all magical and the individual members of the family were supposed to show signs of their specific magic by a certain age, but the main character (a girl about 16-18) had yet to show signs. As such she was considered a dud of some time or non-magical. At a family gathering, she meets a boy a couple years older than her that actually doesn't shun her like her family.
I don't remember much of the rest of the plot other than there was some kind of danger her family was in and her grandmother had given her some kind of clue as to how the main character was to solve this problem. She learns this clue is associated with the clock in grand central station and it ends up taking her back in time and she ends up as a maid in the house of her ancestors. Also, that same boy she met before somehow ends up there.
When I found it, I was looking for another book with "Bewitching" in the title and it popped up in the search, but no longer pops up. I'm sure "Bewitch" must be somewhere in the title as a result. The book cover I remember was black with some kind of night sky related imagery? and I think a witch on it? (but I could also be remembering that all wrong)
Has someone read this book and can tell me what the title is?

Once a Witch by Carolyn MacCullough?

Yes. I think that's right. That sounds right. Thank you