The two at a random area in Eggman's base.

Sonia is searching for a device to hopefully try find Sonic, while Whisper is searching and looting what is there at the base. They encounter each other at some point. When Whisper had found some wisp capsules in a crate. Since the capsules produced light (for some reason), Sonia noticed, being nearby where Whisper is. The two ended up having a chat and Whisper being surprised that Sonic ever had siblings. Because Whisper knows about Sonic it brings up hope for Sonia, that maybe she can find her brother again.