They waited until they could see her -- that is, until they had just about moonskipped past her -- to respond.

"Why, it's Quaver Rest!"
"How ya doin', Quaver?"

Silk Scarf looked around and spotted Cadmium, too.

"Oh, and Cadmium, too! Hiii, Cadmium!"
They waved and generally jumped around like fools, before refocusing.

"How are you doing, Quaver? Poorly, I hope?"
"I think it's that we don't hope. Or, maybe I don't think it's that we don't hope?"

"We've got to get our system of negatives worked out!"
"Or maybe we don't..."