At the start of the animated version of Nimona we are shown the story of Gloreth, and how she was the first person to stand up against a monster that attacked her people.
She is depicted as an adult in armor fighting against a sizable dragon like monster. The scene plays on classical European images of knights and heraldry.
Later on in the film we are shown Gloreth as a child, wearing peasant's clothes, and carrying a toy sword, facing a much smaller monster that is reacting in fear rather than anger after having been attacked by frightened villagers.
Within the scope of the story, is this telling us how events really were, and that the prologue for the movie was a case of either unreliable narration or a story being exaggerated over time (1,000 years are said to have passed since then).
Or was the version of events with Gloreth as a child merely the events that preceded the prologue. Meaning that both scenes happened several years apart with Gloreth seeing Nimona turn into a monster as a child, and then going on to found the Knight's institute as an adult later on in her life, thus setting up the confrontation between her and Nimona that is seen in the prologue.
This question is specifically about the animated version, and not the graphics novel on which it is based, due to there being significant differences in the story.