Our prayers are never wasted. I agree that it is not good for a person to give a bogus story to get sympathy...but if that is what is happening, then it is the poster who is lying that will be subject to the discipline from God.
If we pray for her, and her story is true, then we follow the rules of God by showing compassion for another. If we pray for her and her story is a lie...we are still following Gods will in showing compassion, so God will look on us with favor!
It is never a waste of time to go to God in prayer!! :)
A BIG AMEN to that! :)