I can't decide if that's creepy or not. I mean, she's closer to your age than your dad's, and even if she wasn't that close when you were younger, the relative age difference is shrinking as you both age...
There's an old Abbott and Costello skit about that; Bud tells Lou that if he is 40 and in love with a little girl of 10 (4 times as old), then in 5 years time they will be 15 and 45 (3 times older) then in 15 years time, they will be 30 and 60 (twice as old), and it won't be long before she catches up to him.
So she sees mmore of your "back then" father in you as you age, is that a good thing?
Maybe she's just settling for what she can get more easily.
Maybe she actually likes you.
Why don't you go ask her?
(why do I love to meddle so?)