When an illegitimate child is registered (because father only named if he also attended registration) then it was common for mother's occupation to be listed. Mary Ann was listed as Phillips or McDowell depending on the information she provided to the registrar. Sewer was her occupation- in other words, she likely took in sewing at home to try and support her family. In any case, she would have struggled to look after all her children.
Reading what I've found so far, William & Mary married in Nov.1897 and daughter Mary Ellen born 2 months later. Daughter Sarah born 1899. In 1901 census William is away from home working. Three sons next born (registered with William McDowell as father). Then Mary Ann has illegitimate daughter Annie (1909). By 1911 it looks like she was unable to care for the whole family and eldest daughters are in orphanage*. Son Patrick born 1918.
*an orphan can be a child who has one or two dead parents. I have not been able to find a death for William McDowell (from 1901-1921) but perhaps the Sisters of Mercy also took in children whose parents were not able to care for them.
There's lots more to come but people in this house do persist in wanting meals
