To be fair, denying any degree of help would have been the same as betrayal. Regardless of her poor and delusional moves to achieve "world peace", she remained an Alliance member.
As I said in some other related thread, the big problem of Jaina is that she seemed weirdely obsessed with the idea of peace between Horde and Alliance, even more than Thrall himself was. Which makes it seem like it was more or at least partially tied to her personal issues (validating the willing sacrifice of her father and dispel the shadow of guilt) and then to an actual desire of finding a more reasonable way to deal with the Horde. As a result, Jaina's desperation and consequent frustration seemed to have caged her in some bubble preventing her to fully acknowledge the reality of the world around her.