I tried working back in time to see if I could find your relative Mr. Hagman and Mr. Weaver who was Mary's husband. There wasn't any Aaron Hagman, nor could I find a Mary Hagman for when she was little. It seems Mary's husband must have died pre-1900. Do you have a copy of her death certificate? Hopefully on the death certificate it will list her parents name including her mother's maiden name.I would assume you could get a copy from Grayson County or the TX Dept. of Health. Best wishes in your research.
1930 U.S. Cenus - Texas - Grayson County - Denison -district 21 - Enumeration District21, page 46
Street Address: 725 W. Morton St.
-John W. Weaver, rents home at $15.00/month, age 42, first married at age 21, Born in OK., Father born: Ireland; Mother born: IL,Occupation: Salesman - Grocery, employed, not a military veteran
-Millie M. Weaver, wife, age 38, first married at age 16; Born: TX, Parents born TX ; Occupation: none
-Mary E. Weaver, mother, age 67, widowed, first married at age 20, Born: IL, Parent's born: IL
-Carl C. Weaver, Son, age 20, first married at age 19, Born: T, Father born: OK, Mother born: TX; Occupation: Tinner - Plumbing shop
-Ardena Weaver, Daughter-in-Law, age 19, first married at age 18, Born: OK, Parents born: OK
-James H. Weaver, Son, age 10, Born: TX, Father born: OK, Mother born: TX
-Annie L. Weaver, Daughter, age 2 yrs. and 3 mos. old; Born:TX, Father born: OK, Mother born: TX
1920 U.S. Census - Texas - Grayson County - Denison - Justice of Peace Precinct #2 - Enumeration District: 83, page 10 - T625_1809
-John Wesley Weaver, Head of Household, Rents home, age 33, Married, Born: OK, Father born: Ireland - English, Mother born: IL; Farmer - Farm; works on own account
-Willie May Weaver, Wife, age 27, Married, Born: TX, Father born: TX, Mother born: Tennessee; Occupation: none
-Carl Weaver, Son, age 10, attended school, Born: TX
-Hazel Weaver, Daughter, age 5 yrs. 9 (?) mos. old, Born: TX
-James Herbert Weaver, Son, age 3 mos. old, Born: TX
-Mary Weaver, Mother, age 58, widowed, Born: IL, Parents born in Ohio; Occupation: none
1910 U.S. Census - Texas - Grayson County - Justice Precinct 8 - Enum. District: 107, page 309; T624_1556
-Mary Weaver, Boarder, age 42, widowed, Born: IL, Parents born: IL; Occupation: none
(boards wth the David C. Tumey and family household)
1900 U.S. Census - Texas - Grayson County - Denison, 4th Ward - Enumeration Dist: 100, page313; T623_1639
Street Address: 410 Rusk Ave.
-Mary Weaver, Boarder, June 1874, age 26, Single, Born: IL Parents born: IL; Occupation: none
-Wesley Weaver, Boarder, Birthdate: March 1888, age 12, Born: TX, Parents born: IL; at school