Ash's absence was something Keiko simply had not been ready for.
As the city was slowly cleaned up and letters were being sent to the Royal Council announcing the success of the human army, every now and then, Keiko would look up and say to herself:
Hm. I wonder what Ash wants to do now.
Only to then remember the current state of things and say:
Oh, right.
The fact that Magia was currently strutting through the city in Ash's body left a bad taste in her mouth, but, if Ash indeed agreed to it as Magia had told the group she had, then Keiko wouldn't question that decision on her part.
Instead, she slowly realized she needed to find something to do on her own. That hadn't been the case in so long that the sudden agency almost felt lonely.