“Yolanding”?

From 1281, the widowed Alexander III lost his three children and remarried to remedy the situation. His second wife was Yolande de Dreux, who he married in autumn 1285, but Scotland was plunged into the unknown within five months when he broke his neck, falling from a horse, travelling across the Forth to Kinghorn in Fife to rejoin her. Alexander’s immediate heir was his ill-fated granddaughter Margaret, Maid of Norway, but if Yolande was already carrying a son, as she claimed to be pregnant, the son would supersede Margaret.

Peter Traquair’s Freedom’s Sword (pp.18-19) takes a sceptical view of Yolande’s conduct in the aftermath of Alexander’s death, particularly her claims in this respect: “Towards the end of the year it was clear, whether through miscarriage, phantom pregnancy or deception – according to one hostile English source – she was not pregnant”, although there are rumours that she gave birth to a stillborn son in Clackmannan in late November. She went on to marry Arthur II, Duke of Brittany and definitely bore six children for him.

Yolande de Dreux is not the only case here and some are more definite. Gilbert de Clare, Earl of Gloucester, definitely died without male issue at Bannockburn on 24th June 1314, yet his widow Maud, Robert I‘s sister-in-law, claimed to be pregnant as late as 1316/7. This, save more recent intercourse, was a physical impossibility, which she and her contemporaries must have known (h/t Kathryn Warner)