She said that she junctioned it, but forgot its name, so she could not summon it anymore... meaning she still had it juntioned; it would not make any sence for het to be able to junction the same GF twice, so it is most likely not one of the ones you get in the game...
The way I see it, it must have been an extreemly powerful one, if it grants her to use any magic, plus special magic (mainly The End).