Once Upon a Time has a notorious problem with keeping track of all of their characters. There are so many fairy tales, myths, and legends to cover and so little time in which to cover them. This season alone, they've taken a fresh look at the Rapunzel story and the popularity of Frozen could lead to Kristen Bell making an appearance on OUAT in the future. Season one in particular suffered from many hit-or-miss attempts to stuff as many classic stories into one season as possible, usually with the bonus effect of the Evil Queen or Rumplestiltskin ruining them in some way. Thus, the announcement that Anastasia Griffith is returning to Once Upon a Time as Princess Abigail might be met with more confusion than excitement. After all, she disappeared after her season one story arc and hasn't been heard from or referenced since.
Princess Abigail was a re-imagining of King Midas' daughter from the Greek myth of Midas, the man who turned anything he touched into gold. In the Enchanted Forest, she was engaged to Prince Charming before he met Snow White and the two parted on good terms to be with the people they truly loved. In Storybrooke, she was called Kathryn Nolan and she was the wife of David Nolan, Prince Charming's cursed persona. Kathryn appeared on the scene just as David and Snow White's cursed persona, Mary Margaret, looked to be on the verge of getting together.
In an effort to keep that from happening, Regina not only brought Kathryn to an amnesiac Daid, but she also implanted David with fake memories of his life with Kathryn so he would stay with her instead of leaving her for Mary Margaret. Later, Regina enlisted the help of Rumplestiltskin to fake Kathryn's murder and frame Mary Margaret for the crime. You know, to punish Mary Margaret for something that the curse prevented her from remembering that she even did. Ah, season one Regina. How we loved to hate you.
Kathryn disappeared from the scene was soon as it was discovered that she hadn't really been murdered after all and neither she nor Abigail have appeared since. So why is Once Upon a Time bringing her back? Griffith only mentions Princess Abigail, which at least means that it's likely she only appears in a flashback to Snow or Charming's past, but even that much seems like too much. OUAT underuses the characters that it does have and ends up running out of time to properly explore interesting storylines because they're usually too busy squeezing in more characters and wasting time on flashbacks.
Remember the time Belle got amnesia and spent about four scenes in four episodes thinking that she was a bad girl named Lacey before Rumplestiltskin brought her memories back with a potion? Remember the time Red Riding Hood disappeared from the main cast entirely? And where is my beloved Mulan? As glad as we are to see the return of a familiar face, we'd much prefer if OUAT took the time to properly develop more than just a handful of characters before they start shoving more in. Surely Zelena's plan to return to the past doesn't involve playing matchmaker with the same couple her sister tried to set up?