Femme Fatale was born a few years after My Little Pony: Friendship is Magic. Riff Wrath left Enmity to raise his family. Trixie would teach young Femme to perform magic tricks. In Femme Fatale's teen years, Riff Wrath returned to Enmity and brought his daughter to become an agent.
In public, she would use her magic to hide her wings and change her mane-style. She would go under the name "Star Cross".
One day, she met Noble Knight, a Steed Knight of the Chess Table, and son of her parents' arch-rivals, Sir Sheath and Twilight Sparkle. As Star Cross, they recently began dating and things seem pretty good between them. Riff Wrath thought this could be a good opportunity to get some payback from Sir Sheath, his wife, and their friends for all their encounters in the past. So he involved Trixie and Femme in his plan to get them.
While Sheath and Twilight were having a reunion with their old friends, Noble Knight and Femme Fatale (as "Star Cross") were out together. But Noble's sisters, Shrove Ash and Star Light, knew something was wrong, So they followed them. Femme Fatale revealed to Noble her true identity, and he realized that he was in a trap set by her parents. They going to use him as bait to bring their enemies to them, which they did.
Femme Fatale was told to watch Noble. At the time, they were revealing they really did have feeling for each other. While Riff Wrath and Trixie was talking to their long-time foes, Strove Ash and Star Light knocked Femme out and "rescued" their brother. Then all three went downstair to assist their parent, and cover Riff Wrath and Trixie. Femme Fatale, now conscious, had everypony covered, even her parents. Her time with Noble Knight has given her a whole new outlook on life. Her father was shocked, but her mother was happy to know that her daughter's in love. Riff Wrath started getting depress, thinking he's failure to his job and his family. So his wife, his daughter, even their enemies cheered him up. But in the end, she allowed her and her parents to escape, knowing that her father needs her.
Noble Knight and Femme Fatale come across each other every now and then, keeping a relationship while maintaining their family rivalry.