Zij is getrouwd met William de Grandison, 1st Baron Grandison.
Zij zijn getrouwd in het jaar 1286 te Donyatt, Somerset, England, zij was toen 19 jaar oud.
Kind(eren):
Blanche 'Sibilla' de Tregoz, of Switzerland<br>Gender: Female<br>Birth: 1267 - Harpenden, Hertfordshire, England<br>Occupation: Co-heir of her father.<br>Marriage: Spouse: William de Grandison - 1285 - England<br>Death: Apr 23 1323 - Grandison, Lake Neuchatel, Switzerland<br>Burial: Dore, Sussex, England<br>Father: John Tregoz<br>Mother: Mabel FitzWarin<br>Husband: William de Grandison<br>Children: Agnes Bardolph (born de Grandison), John de Grandison (born de Grandeson), Mabilia de Paleshull (born de Grandison), Catherine de Montagu (born de Grandison), Countess of Salisbury, Otho de Grandison, Piers Grandison<br>Sibling: Clarice de la Warre (born de Tregoz)