Vilsa Nara was just playing version 11.3 on your itch.io (with Firefox, on a Mac, for full disclosure). I restarted from the start, because I read on the patchnotes that you changed the inner stronghold part of the prologue. (I appreciate them changes too, good decision.) Thing is, after Jenna escapes and comes out of the abandoned house, she goes south and... nothing. There's a map that refuses to load, she's just stuck there, below the screen, in some invisible (to the gamer) place.
I also had trouble with her speed skill in the first couple of battle: couldn't use it (not hard to win even without that skill), but using the skill worked fine in the final battle against Leath. Can't figure out why it worked there, but not before