1353 IPMs for Joan's mother Alice and for Alice's cousin Thomas Achard suggest that Joan was born in 1353. She was said to be age 1½ on 25 May 1355, [1] age 1 on 25 June 1355, [2] and age 7 and more on 4 or 11 November 1360. [3]
[1] Calendar of Inquisitions Post Mortem, Vol. 10, Edward III (London: HMSO, 1921), 205, [HathiTrust].
[2] Calendar of Inquisitions Post Mortem, Vol. 10, Edward III (London: HMSO, 1921), 196, [HathiTrust].
[3] Calendar of Inquisitions Post Mortem, Vol. 10, Edward III (London: HMSO, 1921), 549, [HathiTrust].