He tells a great story and does list many sources, but they are all for the ancestry of Charles, 2nd Lord Howard, who did not have a daughter named Mary. Henry Scott's mother was Joan ---, wife of Edmund Scott (see below).
Charles, 2nd Lord Howard had two wives and seven children:
1st wife: Hon. Catherine Carey, b. 1549, Hunsdon, Hertfordshire
Married: Jul 1563, Hunsdon, Herts.
1. Lady Frances Howard
2. Lady Margaret Howard
3. Lady Elizabeth Howard
4. William Howard, Baron Howard of Effingham , b. 27 Dec 1577
5. Charles Howard, 2nd Earl of Nottingham , b. 17 Sep 1579, The Manor Place, Bletchingley
2nd wife: Lady Margaret Stewart
Married: Sep 1603
1. Charles Howard, 3rd Earl of Nottingham , b. 25 Dec 1610, Haling House
2. Lady Anne Howard, b. Abt 1612
The parents of Henry Scott, husband of Martha Whatlock, were Edmund Scott and his wife, Joan ----. The Scott family was of Bradfield Saint George and Rattlesden, both co. Suffolk, England, per parish registers.