Why Didn't Sarah Recognize Carver??

In Season 2 when Carver visits the house while only Clementine and Sarah are there, Sarah tells Clem she thinks she knows him and that he can't see her. So why is it that when everyone came back she just told them, "A man was here. Someone was at the cabin." The group escaped Carver at the very most 9 months prior (based on Rebecca being pregnant and there being a chance it was his). Even if Sarah didn't immediately recognize him through the window or door, when he came in the house she was peaking and listening, so she should have recognized it was Carver. It wasn't like she last saw him years ago or as a little girl...

TLDR: In Season 2, why didn't Sarah just tell the group that Carver came to the house?? How did she not recognize him?