While searching on my own Calvert family and for Alonzo Calvert of Enoch's line,I stumbled across the following...Effie L? is a Calvert I believe who married William Berry.
US Census, 1900: District of Colombia, Washington County, Roll 162 Book 2, Page 121, Washington Twp. HH #19 364/335. WIlliam A Berry,Oct 1868 age 31 MD MD MD Effie LJan 1875 age 24 DC DC DC AnnieAug 1844 age 55 DC MA WV
US Census 1910: District of Columbia, WASHINGTON, Roll 149 Book 3, Page 42a, ED 25, image 1 HH #5 Annie T in 1910 Census age 55 Wd DC MA WV living in same "mother" FayC Berryage 28 Wd DC DC DC head of Household
Note the age in 1900 is 55 and the same in 1910. I think it should be 65 and Fay is Effie in 1900 Census also about 10 years off...
Annie T is the grandmother of Fay C, the age is wrong for her but not Fay C. Thus a Daughter of William Berry and Effie. The HH has no children and both women show WD(Widow)
Whichever or what ever, This Effie is a Calvert father born MA, at least I believe this is what is true.