Context: Arriving in Hell just minutes before midnight, Adrian begins the process of taking over Hell by pushing what remains of his father aside and sitting on the throne, rising to Central Park, and starting a riotous party. Meanwhile, Nicky wakes up in Heaven as a reward for sacrificing himself and meets his mother (Reese Witherspoon), an angel who tells him he can defeat Adrian with the Inner Light he inherited from her. After she gives him a mysterious orb, he goes to Central Park. Adrian appears to win a pitched battle by locking Nicky in the flask and turning himself into a bat, but Nicky escapes from the flask. When he shatters the orb, Ozzy Osbourne appears, bites Adrian's head off, and spits it into the flask.

Question: who plays nikki's mom in little nicky?
Steam of consciousness below:
The relevant sentence in the passage is: Meanwhile, Nicky wakes up in Heaven as a reward for sacrificing himself and meets his mother (Reese Witherspoon), an angel who tells him he can defeat Adrian with the Inner Light he inherited from her.
So, the answer is Reese Witherspoon.