Sylphy felt a sense of obligation.
Maybe it was because Sylphy had been taught how to manage all of the household affairs from Lilia.
Putting it in the right context, Lilia was something like Sylphy's Shisho.
Much like how Roxy was for me.
In that way, it's only natural one gives them their due respect.
"Then, Auntie Zenith, it's been a while since I've seen you as well.