His older sister Ellen looks after him in the 1861 Census Lodging with the Duggans,
census uk 1861
Name: Peter Mooney
Event Place: Liverpool, Lancashire, England, United Kingdom
Event Place (Original): St Simon, Liverpool, Liverpool, Lancashire, England
County: Lancashire
Parish: St Simon
Ecclesiastical Parish: St Simon New Parish
Registration District: Liverpool
Residence Note: Hill Street
Age: 15
Occupation: Errand Boy
Birth Year (Estimated): 1846
Birthplace: Liverpool, Lancashire
Relationship to Head of Household: Lodger
Relationship to Head of Household (Original): Lodger
Page Number: 37
Registration Number: RG09
Piece/Folio: 2690 / 64
Affiliate Record Type: Household
Thomas Duggan Head Male 36 Liverpool, Lancashire
Mary Duggan Wife Female 27 Ireland
Margaret Ann Duggan Daughter Female 3 Liverpool, Lancashire
John Duggan Son Male 1 Liverpool, Lancashire
Ellen Mooney Lodger Female 23 Liverpool, Lancashire
Peter Mooney Lodger Male 15 Liverpool, Lancashire
I know you already have this information but posting for anyone else who may be having a look.
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