Nimona can't help it: she looses a peal of laughter, as bright as her smile, and leaps off the edge of the alcove.

Before she's fallen more than a foot, she collapses back into that streak of pink light, instantly swirling and reforming into a bat just like Ylva. Still laughing, she loops around her. "You're like me!"

Seems like Ylva is more than forgiven for scaring Nimona away.