Our own decision-making abilities can become depleted over the course of the day causing indecision or poor choices, but choosing on behalf of someone else is an enjoyable task that doesn't suffer the same pitfalls.
She highlights a paper by researcher Iris Schneider which finds that indecisive people are more likely to look at different perspectives and use them to come to a better decision.
And if the rains do come, that proves the efficacy of prayer-and no one says that it rather proves the irresolution of God and his readiness to abandon his plan.