The night before after he went up to go to bed his wife started in on him. So he changed it so that Tiffani is a year old and she has Sally looks. He had also changed it so that her skill level is that of a infant. He then took and removed all memories of her life had been erased.
He then had changed Sally's age from 16 to 24. He had also has it so that Sally is a High School graduate and that she had a perfect 4.0 grade point average. He also has it where Sally has memories of giving birth to Tiffani, Robin, & Sarah. He had made it so that Tiffani parents are now Sally's. We see that Sally was a twin so now it shows that Sally's parents only had one child and her name is Suzanne.
He has it set up to take effect about 1 A.M. because he figures everyone will be asleep.