Which factor is NOT important when assessing a female mouse with newborn pups?

When assessing a female mouse with newborn pups, the dam's weight is not as immediate a concern compared to factors that impact the well-being and survival of the pups. Evaluating the condition of the nest provides insight into the care and environment the pups are being raised in. A well-maintained nest can significantly affect the health and growth of the pups.

The number of pups is critical as it can indicate the success of the dam in raising her litter and can also affect her resources, like milk production. If the dam is lying on the pups, this could pose a serious risk to their survival, as it may lead to injury or suffocation.

In contrast, while the dam's weight is important for overall health, it does not have an immediate impact on the immediate care or safety of the newborn pups as the other factors do. Thus, while a healthy weight is beneficial for the dam's well-being, it is not as crucial in the acute assessment of her care for the pups in that moment.