Is the wife considered negligent or sinful for severing ties of kinship if she does not frequently visit her husband's family or help them with their housework, due to her constant preoccupation with caring for her children and home, and her husband's absence?

You are not legally obligated to help your husband's family or serve them with household chores, and there is no sin upon you for not doing so, nor are you considered a severer of kinship ties. However, you should observe their rights as neighbors and Muslims by treating them gently, offering kindness and good deeds, initiating greetings, visiting them when sick, and sharing in their joys and sorrows, while being careful not to neglect your duties towards your children and home.