I Have Your Wife: The fairies kidnap Red's brother. Morwenna kidnapped Tanya's mother when she was a baby, in order to blackmail Florence into completing the pact.
Missing Mom: The series provides a few examples of this:
Red's parents died in a car crush.
Amos's wife left the family when Warwick was only a child.
Fabian's mother died when he was a child.
The Reveal: Morwenna Bloom was evil all along and was trying to trick Tanya into getting trapped in the Fairy Realm, so that Morwenna would be free to return to the human world. Florence was acting aloof towards her granddaughter because she wanted to protect her.