This is in the same continuity as another fic of mine: The Storybrooke Dodger
Emma, Killian, and their adoptive son Jack (AKA the Artful Dodger) went to Zelena's house for dinner. Zelena greeted them at the door and shook hands with Dodger. "It is good to meet you" she said. Robin looked up to see who was arriving. Usually she and Emma got along well but this time Robin wasn't happy to see Emma. She pointed at Emma and said "You did bad thing".
"What did I do?" Emma asked.
"You put spell on me" Robin said "made me different".
"Oh" Emma said guiltily, unsure what to say at that point.
"Sorry" Zelena said "that meddlesome blue fairy told her".
Robin went into her room to hide. Emma wasn't sure what to do. The child had finally found out she was responsible for all her problems. How could she explain herself?
"Lemme talk to her" The Dodger said, looking like he just had an amazing idea.
"Why do I feel like you're up to something?" Emma asked.
"Who me?" The Dodger said, feigning innocence. He knew Emma didn't buy it, but it was a sort of game they played. Emma looked nervous while Dodger went into Robin's room.
Robin was on her bed, playing with dolls.
"Twas a dirty trick Emma played on you, wasn't it?" Dodger said.
"Yeah" Robin said.
"Wanna play a dirty trick on Emma?" Dodger asked, with a glimmer in his eye.
"Yeah" Robin said, jumping up and down.
"I'll tell you a secret" Dodger said "Emma was almost eaten by a spider once".
About fifteen minutes later, Dodger called for Emma to come into the room. Emma opened the door, expecting to have to try and apologize to Robin. When she opened the door, she wound up walking straight into a wall of fake webbing. Emma screeched from the sudden reminder of her near-death experience. Dodger and Robin both laughed hysterically.
"Jack, are you teaching her to be bad?" Emma scolded.
Robin hugged Emma's leg.
"Hey, in her mind, now you're square" Dodger explained.