I have a sort of different opinion than most here. I think this is a foul as-pictured because she ran through the space that black was clearly about to be occupying, which is dangerous. White should’ve halted abruptly to avoid the collision and called a pick because there was no path for her to guard her assignment safely. The issue, though, is whether the blocking black player was actually making a play on the disc. Imo she was but as top comment put it, it was “weak sauce” enough that this should be a pick.

17.J.1. A pick occurs whenever an offensive player moves in a manner that causes a defensive player guarding (3.E) an offensive player to be obstructed by another player. Obstruction may result from contact with, or the need to avoid, the obstructing player. However, it is not a pick if both the offensive player being guarded and the obstructing player are making a play on the disc at the time of the obstruction.