Isabella was the second of three children born to John de Warenne, 6th Earl of Surrey and his wife Alice de Lusignan, maternal half-sister of Henry III of England.

Their mother died while giving birth to Isabella's younger brother, William, who was killed in a tournament after he had married Joan de Vere and sired two children.

On about 9 February 1281 Isabella married John Balliol, who had a claim to the Scottish throne.

It has been established that the couple had at least one child: However, other children have been linked to the couple as other possible issue: It is believed that Isabella did not live to see her husband become King of Scotland, so it is likely that she died before 1292, when her husband ascended to the throne.

However, some are of the opinion that Isabella did survive long enough to see her husband succeed and then abdicate.