Looks like first Isabella died.

Lawson's Burial Record
QUAYLE, Isabel infant Patrick 21 Mar 1839

IGI
Name: Isabella Quayle
Gender: Female
Baptism/Christening Date: 03 Feb 1839
Baptism/Christening Place: PATRICK,ISLE OF MAN,ENGLAND
Birth Date:
Birthplace:
Death Date: 21 Mar 1839
Name Note:
Race:
Father's Name: Wm Quayle
Father's Birthplace:
Father's Age:
Mother's Name: Anne Anderson
Mother's Birthplace:
Mother's Age:
Indexing Project (Batch) Number: C03824-1
System Origin: England-ODM
Source Film Number: 106176, 106738
Reference Number:

Patrick Burial Register
Isabel Quayle infant of William buried 21 Mar 1839

Have you found Wm Quayle/Ann Anderson in census?
Have you determined Ann's line?