She was the daughter of Laura Martinozzi and James VII/II's second wife. Her Wikipedia article is here. It has been theorized that the lullaby "Rock-a-bye baby" "refers to events immediately preceding the Glorious Revolution. The baby is supposed to be the son of James VII/II, who was widely believed to be someone else's child smuggled into the birthing room in order to provide a Catholic heir for James. The "wind" may be that political "wind" or force "blowing" or coming from the Netherlands bringing James' nephew and son-in-law, William III of England, a.k.a. William of Orange, who would eventually depose King James II in the revolution. The "cradle" is the royal House of Stuart.