By far she is the worst main character in any fire emblem game. Even in Sacred Stones she is the worst character. I choose the Ephraim path anytime I play simply because I dont want to deal with Erika.
She rarely gets Defense or Resistance, so if she gets hit twice, she can loose up to half her health. In the final battle I had her at level 15, and she took a single hit from a lance. Then Lyon hit her, and killed her instantly.
Ephraim was hit by three enemies, and Lyon and survived.
Ross can even kill the final boss in two hits with Garm. Erika does at most 60 damage in two hits (if you get lucky and max her out completely, usually she does around 15-20 damage per hit on the final boss), but she will die instantly in the enemies' turn.
