Look, Ianto. You're one of the only people she considers a friend in this... place. You've given her coffee and you've done shenanigans with her and you've told her secrets. Space buddies equals practically BFFs as far as she's concerned and so, yeah. She's gonna notice if suddenly, something's a little off.

When he says that his ex woke up, her teasing smile drops from her face and she immediately wonders how John's doing, too, before she sighs a little and asks, "Sounds complicated. What's happened?"