If there are no humans in Paradise, then how does the story of the woman who gave water to a dog and entered Paradise fit in?

The first to enter Paradise is our Prophet Muhammad, peace and blessings be upon him. He is the first to knock on its gate, and the first to be granted permission to enter after his grave splits open for him. The woman who gave water to the dog was forgiven because of her deed, not that she entered Paradise at the time she gave water to the dog in this world.