1910 census :

1920 census:
pag 1

pag 2

I remember that Lena was not a member of Frances Birillo family in 1930 .. so maybe she was married... but also it is possible another explanation....
I no saved the 1930 census sorry.. I hope that my suggestion is correct.... I cannot find the marriage record; I searched from 1920(!) to 1937 and nobody Lena Birilli...
http://stevemorse.org/vital/nymarriages ... ndex=brideI found the marriage of:
Birilli Domenico Jun 2 1928 14515 (1928) Manhattan
Bodalomenti Pietrina Jun 2 1928 14515 (1928) Manhattan
and
Birilli Joseph Jul 30 1921 30156 (1921) Manhattan
Fonn Anne Jul 30 1921 30156 (1921) Manhattan
abt Joseph Birilli (Lena brother) birthdate I found it in a genealogic tree on ancestry.com
Joseph Birilli
Birth 5 Oct 1897 in Castroreale, Sicilia, Italy
Death Living
Death 25 Aug 1993 in Burlington, Skagit, Washington
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parents:
Antonio Birilli
1869 – 1918
Frances Birilli
1870 – ..
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spouse:
Anna Fronn (or Fonn)
1902 – 1993
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Joseph siblings:
Maggie Birilli b.1894
– Sarah Birilli b.1901
– Dominick Birilli b.1905
– Lena Birilli b.1909
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all the best,
suanj