Seven the Hard Way (2) - S7-E16
Continuity mistake: When Topanga joins the group hug, the piece of paper that Eric wrote on is underneath her. When Cory joins in, the paper has disappeared. It then reappears when Mr. Feeny dismisses everyone. (00:20:10 - 00:20:45)
The War (1) - S7-E15
Continuity mistake: After Rachel sprays water all over Cory, the amount of wetness on his shirt varies throughout the scene. (00:05:53 - 00:09:05)
I'm Gonna Be Like You, Dad - S7-E14
Continuity mistake: When Topanga, Shawn and Angela are hanging out in Cory and Topanga's dorm anticipating Cory's return from the doctor, the slice of pizza that Angela is eating goes from having a small bite taken out of it, to being halfway gone, and back to having one bite taken out of it. (00:12:07 - 00:14:02)
Continuity mistake: When the voice on the intercom is saying "Paging Dr. Chocolate Pudding," Cory's right hand is on Topanga's right arm, and her hands are in her lap. When the shot changes, both of his hands are suddenly resting on his stomach, and her right hand is suddenly resting on his left leg. (00:07:23)
Continuity mistake: When Shawn stands up on the chair to propose a toast, Eric is at his 9 o'clock. When shot changes, Shawn has instantly rotated his body so that Eric is now at his 6 o'clock. (00:16:47)
Continuity mistake: When Morgan is telling Topanga that she wouldn't use her bridesmaid's dress to wipe her ass, she gets cut off by Alan who covers her mouth with his left hand and then begins dragging her out of the reception hall. When the shot changes, he is covering her mouth with his right hand. (00:17:22)
Continuity mistake: When Eric is hugging Angela, her arm is on his shoulder. In the next shot, when Jack is saying "How am I going to survive without money?" you can see, between him and Rachel, that Angela now has her arm on Eric's back. (00:16:58)
Continuity mistake: When Topanga puts the bucket in the garbage bag, she is holding the bag with her left arm and has her right arm in it. In the next shot, she is holding the bag with her right arm. (00:00:36)
She's Having My Baby Back Ribs - S7-E17
Continuity mistake: When Cory gets off the bed he leans against the dresser and his hands are behind him. When Topanga walks in the room, his hands are by his sides. (00:03:50)
The War (1) - S7-E15
Continuity mistake: When the show starts, Angela and Shawn are kissing. The shot changes to Topanga and Cory, who has popcorn on his shirt. The shot goes back to Shawn and Angela, when Cory is shown again, the popcorn is gone. Again the shot changes to Shawn and Angela, then back to Cory and the popcorn reappears.
Continuity mistake: When the spider is walking on Eric, it makes it past his fingers and has some legs on his wrist before the shot changes. In the next shot, the spider is still walking on his fingers. (00:16:17)
Continuity mistake: In the season 7 episode "I'm Gonna Be Like You, Dad" Alan and Amy's youngest son Joshua is shown to be an infant. However in this episode, which takes place roughly 4 months after the aforementioned episode, he is shown to be around 2 years old.
Answer: Topanga's middle name is never specified. Considering her sister's name is Nebula Stop-the-war Lawrence, Topanga's is probably something equally unusual.