This census sure looks like it places Hanna in this family Michael John [MC]CROSSON was b12-30-1904,Perhaps Hanna was b aft the 1900 census was enumerated.
I'm posting this census for others to view, if need be.
Robert Mchugh, "United States Census, 1920" Name: Robert Mchugh Titles and Terms: Event Type: Census Event Year: 1920 Event Place: Philadelphia Ward 36, Philadelphia, Pennsylvania, United States District: 1285 Gender: Male Age: 24 Marital Status: Married Race: White Race (Original): White Can Read: Yes Can Write: Yes Relationship to Head of Household: Head Relationship to Head of Household (Original): Head Own or Rent: Rent Birth Year (Estimated): 1896 Birthplace: Scotland Immigration Year: 1913 Father's Birthplace: Ireland Mother's Birthplace: Ireland Sheet Number and Letter: 7B Household ID: 141 Line Number: 96 Affiliate Name: The U.S. National Archives and Records Administration (NARA) Affiliate Publication Number: T625 GS Film number: 1821638 Digital Folder Number: 004383804 Image Number: 01004 Household Gender Age Birthplace Head Robert Mchugh M 24 Scotland Wife Hannah Mchugh F 20 Pennsylvania Daughter Mary Mchugh F 2 Pennsylvania Daughter Sarah Mchugh F 0 Pennsylvania Brother-in-law Michael Mccrosson M 15 Pennsylvania Mother-in-law Mary Mc Crosson F 49 Ireland =========================== Robert MC HUGH b 5-16-1895 Glasgow Scotland; chauffeur; blue eyes/blk hair...WWI Draft Reg
1930 Philadelphia MC CUE Albert!! 34 Scot; chauffeur Hannah 30 PA Mary 12 PA Sarah 10 PA Catherine 9 PA CROSSIN, Mary 59 N. Ireland ============================ 1940 he is again MC CUE, as is the marriage record Mary CROSSIN not with the family There is a Hannah MC CUE 12-1899; d 7-1974 Philadelphia. If this is she, I think she was b 12-1900.