A couple of choices from 1910 for Mrs Riddock in Massachusetts.
1920 Census For New Bedford Ward 6, Bristol, MassachusettsReta Riddoch 48 Think his name should be Peter -Born Scotland. Immigrated 1872
Agnes Riddoch 47 Born Scotland. Immigrated 1880
Jane Riddoch 20 Born Connecticut
John B Riddoch 18 Born Connecticut
Margaret Riddoch 19 Born Connnecticut
Marion Riddoch 17 Born Connecticut
Flora Riddoch 10 Born Massachusetts
Ruth Riddoch 8 Born Massachusetts
Charles Riddoch 6 Born Massachusetts
1910 Census Andover, Essex, Massachusetts (Will really have to find this in 1900 to show her husband)
Helen Riddock 56 Born Scotland. Widowed. Immigrated 1888
Charles M Riddock 24 Son Born Scotland. Immigrated 1888
Typically she was widowed in 1900 Census Andover, Essex, Massachusetts as well and could have been married twice
Helen Riddock 46 Had 6 children and 6 survive) Widowed
Charles Riddock 15 Born Scotland
Helen M Ritchie 21 Daughter Born Scotland. Immigrated 1888
Alexander Ritchie 19 Son Born Scotland
Margaret B Steere 76 Boarder
Gets worse - I can see a Helen Ritchie in Newhills. Aberdeen with 4 children on the 1881 Scotland Census - 2 of which are Helen M Aged 2 and Alexander 3 months which would fit her but again no husband. A brother lives with her and he is Joseph W Milton but it does'nt say what her marital status is
Can you unravel anything from all that