As it stands this sentence is a little ambiguous, only your title tells us for sure that it's her face, not the house, that has a freshness.
If you mean that whether she was inside or outside, her face had a healthy glow or bloom, as it's sometimes called, then I think "freshness" is a good term.
Perhaps: "Even inside the house, her face had a freshness to it." or "… had a healthy glow".
Or, "She had a fresh complexion, even inside her house".