Lady Mary Bertie Peerage person ID=468643 Parents Jane Brownlow Peregrine Bertie, 2nd Duke of Ancaster and Kesteven Children Bertie Greatheed Siblings Peregrine Bertie, 3rd Duke of Ancaster and Kesteven Lady Jane Bertie Brownlow Bertie, 5th Duke of Ancaster and Kesteven Caroline Bertie unknown daughter Bertie Albinia Beckford Partners Samuel Greatheed