"Then what should I do the next time she shows up?"

It doesn't sound particularly passive-aggressive or anything - there's no 'what else can I do' sort of meaning to it. It's always hard to guess with Ange's tone whether she means something genuinely or in a deadpan way though, but this is genuine. She's willing to defer to Lapis' opinion on the matter.

"Should I just leave her alone and let you sit in that other place until she switches back?"