Apparently, Mary's father was a Robert:
The Ipswich Journal 23 May 1846
13th inst, at Bath, aged 52 years, Mary, the beloved wife of Mr Fortt, and youngest daughter of the late Mr. Robert Risk, formerly of Badingham, farmer.
The date on the Findagrave entry mentioned in an earlier post would be the burial date. Her son William is in the same grave.
The following may or may not be the same Robert:
Bury and Norwich Post 25 April 1827
On the 6th inst. at Framlingham, aged 74, Elizabeth, wife of Mr. Robert Fisk, formerly of Badingham, farmer.