Isabella, Countess of Menteith

Isabella, Countess of Menteith (1217 – 1272) was the eldest daughter of Muireadhach II, Mormaer of Menteith. When the old mormaer died without legitimate male heir in 1233, the province passed to Isabella.

Source: Wikipedia — Isabella, Countess of Menteith (CC BY-SA 4.0)