Faolan tries to do his best at wrangling Lily out of Sirius' face but he's not used to having to do this himself, and while he has seen Lancelot do so countless times, he isn't certain how he does it. Perhaps an inherent command that she has come to understand from only the man himself.

He glances to Sirius before back at Lily herself. "I suppose it couldn't hurt," he says, after a moment. "What do you think?" he asks her, still not certain whether she would be able to understand him or not, but making the effort despite himself. "Do you think you can help us find Lancelot?" He tries to emphasize the last two words. If anything, surely her doggy brain can understand that much?