To support the above, in the 1940 census I find:
Thomas J Neary, aged 67, married
Residence in 1935; Brookline, Mass.
Registered as living on Ward 2, Worcester, Worcester City, Worcester, Massachusetts
Marie Neary, aged 62 (again the age is a bit off), married
Born Erie (Eire or Erin = Ireland)
HEAD OF HOUSEHOLD
Residence in 1935; Brookline, Mass
Registered as living in Brookline, Mass.
So although Marie is married, her husband is not living in the same household, therefore she is head.
And now the beautiful part:
Living with her in the same household is:
Frank Tiernan, aged 56, widowed
Brother of Marie
Born Erie (Eire / Erin)