When the Devil decided something, she usually kept to what she had decided. That's why she had moved in with Crowley without actually asking. She'd just told him she was moving in and now she was. At least for a little while. She was around, doing who knew what when she realized that there was someone else there.
Peeking her head around the kitchen entryway, she smirked when she saw it was the angel. "Aziraphale. What are you doing here?" she asked like maybe she was making sure he wasn't trespassing. She might already know why he was there, but it was fun to poke at him.