@James20
You forget that she can create as much mass as she wants (her thread isn't weightless), and she can shoot them at a very high velocity (otherwise she'd be dead by the time her thread hits, not to mention her thread moves fast enough to actually hurt her despite being soft).
Also, I fail to see how levitation implies that standard rocketry rules no longer apply. I mean, come on! Our rockets didn't magically stop working as soon as we invented Maglev (magnetic levitation) trains, or did I miss something since the 80s?
But if we're going to go as far as to say what makes "more sense":
Why not just ride on the damn thread?
She can create thread with enough energy to displace her body, so why not ride on it like riding a broom or magic carpet?
Why not shoot it to where she wants to be headed, and keep the thread connected to her butt, so the recoil would drag her towards where the thread is headed?
Why sacrifice HP by using a method that is...
1. completely unintuitive and
2. offers no apparent benefit compared to other, significantly more intuitive methods?
I mean, seriously, what she's doing is like kicking herself in the butt to move forward, instead of just walking. It's incredibly weird to look at, magic or not.