Will this approach, although we understand its “helpfulness,” produce a perceptible difference in the girl’s behavior and tolerance of animals?

If both a Protocol session and the subconscious channeling are done, this can be arranged with a minimum of a few sessions, but it will take that to undo the sum total of what is present in the akashic record. It is more than the untimely death, there were other situations as well, as that most recent unfortunate tragedy was a karmic repeat of prior difficulty of a similar nature. Doing the subconscious channeling would enable more quickly to go through a series of such experiences and reframe them for the benefit of the subconscious directly, and that work would be quite helpful to speed things up.