Is it permissible for a mother to move three steps to the left during prayer to pick up her crying child from the bed?

A mother is not permitted to take more than two consecutive steps during prayer to reach her child, because doing so is considered "excessive action" which invalidates the prayer. However, if she pauses after two steps and then takes a third step, there is no harm in that. If her child's crying disturbs her, she should shorten the prayer with a taslim that does not violate its pillars and obligations, and then conclude the prayer. If she fears for the child's perishing, she must interrupt her prayer to save him and then resume her prayer.