Can flip effects be in response to something?
No, she cannot.

Monsters are only flipped face up under certain conditions:


Flip summon - a flip summon during the main phase, like you describe in your question.
Damage step - During the battle phase when a face down defense position monster is attacked.
Resolving an effect - When an effect specifically instructs to flip a monster face up, or instructs you to change a face down monster into attack position, which requires the monster become face up.