"Yet it appeared to me that we were all, at Bly, sufficiently sacrificed to make that venial"
Table of the Mortal Sins (detail) (c.1475-80)
Public DomainTable of the Mortal Sins (detail) (c.1475-80) - Credit: Hieronymus Bosch

Venial sins, defined in opposition to mortal sins, are those sins which are considered to be relatively minor and which can be atoned for through temporal punishment, rather than separating the sinner from God and occasioning his or her eternal damnation. There is not a specific list of venial sins; rather, they are defined as those which an individual commits without full consent or knowledge, or which do not fall within the criteria of grave matter. The governess’s remarks suggest that she, as well as the children and Mrs Grose, has already transgressed so far against the law of God as to consign her soul to hell.

The Catholic Encyclopedia’s entry on sin, its causes and effects, and how it is categorized, can be found here.