@Trapaholic - they've been away from home for 4 days. Since they entered in ch. 18, night has been shown only twice - between ch21 and 22, and starting from the evening of the zombie attack in ch. 24. That's two days.
This chapter starts with "2 days after the undead uproar", so 4 days total.
@FgoSegul - Lefi isn't a loli. She looks like a slim teenager.