This family is getting difficult to piece together. I have just found your Ruth Snell b.Norwich, aged 2 at Smaley Lane, Melford in 1871 Census with her mother, Mary, aged 25. The head of the usehold is Frank Snell, aged 27 (Mary's brother!!).
In 1851 Mary Ann, aged 5 is with her mother, Sarah (but her age is given as only 30) and Sarah is with William Howe, aged 32 (b.Glemsford), listed as his housekeeper with Mary Ann, 5 and a son, Thomas, aged 3 months.
In 1861 Sarah is listed as wife (but age 40) with William Howe and three children, Mary A, aged 15, Thomas, 10 and William, 5 (all listed as Howe).
If it is the same Sarah she is listed as Snell, aged 54 (a more accurate age) with her widowed mother, Ann in High Street, Lavenham. Sarah Snell aged 65 was living with William and Elizabeth Turner in High Street, Lavenham. Sarah was buried 1887 at Lavenham.
Can we be sure that the Sarah who is clearly your ancestor, is the same one who is back at Lavenham in 1871 and 1881?
Why can't I find Frank Snell before 1871 Census?
Regards, Steve