I'd bet at this point she's quite powerful. Maybe not quite to the level of Thorn (Street Legends places him at a magic rating of 14!) given he's been active since as early as 2036, but she's probably quite a high level initiate at this point.
There're stats for her floating around in some book, but I can't seem to remember which one off the top of my head (somewhere in
Dawn of the Artifacts, but I don't recall which one).
That said, in terms of
magical power, I'd personally peg her higher than Thorn. She might not be as well-rounded (at both combat, stealth, and social manipulation) as he is, but that's because he's sunk a lot of time and training (IE, karma points) into skills across a wide variety of groups. For just plain magical whammy, I'd go with Harlequin's apprentice, well before I'd go with Agent Thorn, in my personal headcanon.
...all that said, though, I think her power comes more from that nonstop magical training with a lunatic who's a
literally top-tier spellcaster, and less from just inherited power due to her lineage or whatnot.