Caroline opened her mouth to respond and then promptly closed it when he mentioned buying a house. That was...unexpected. Though Caroline figured Lizzie would eventually move in with Ty at some point, she wasn't aware of the timeline. Hearing he bought a house made Caroline realize that deadline might be closer than she thought.
"That's great," Caroline replied finally. "I'm guessing that means you'll be asking Lizzie to move in with you soon." Sure, she'd been surprised at the admittance, but Caroline was pleased at the thought of her daughter and Ty moving in together. Of them taking that next step in their lives.