Adhering to the facts of this situation, is there an instance where it’s ambiguous whether “she” or “it” is acting?
I'm not sure what you're asking. In this case the 'it' in the declaration is her. The ambiguity, such as it is, is whether the declaration applies to her in her private life as well as at work, or not. I would guess it's not intended to, but then it is not clear. Also, it's only relevant if the bone of contention is based on her not being able to boycott Israel in her private life, and I'm not even sure that's the bone of her contention, or the only one. In fact, reading her case, it doesn't seem to be the basis of her case. She seems to me to be objecting to an anti-boycott-Israel law even as it applies to her work, and possibly to such laws in general, on principle.
Looking at the similar case in Kansas that's already gone through the legal system there, it appears that authorities may have to water down the terms of such things so as, for example, to exclude individual, sole proprietors such as her. But I suppose the Texas Courts may not necessarily be bound by decisions made by courts in Kansas, so maybe there will be a different outcome in Texas.
In any case, that, if it happened, would still allow a modified version of the law to pertain (for larger businesses). In other words, it wouldn't shed much light on the general arguments for or against such laws in principle. But for her, the woman in the OP, it would mean she would in theory be able to get her job back without having to sign a declaration of that sort.