Lesley,
Nothing in Onchan on either Ann or Patrick
I'll keep an eye out for them elsewhere

Michael Old Yard
B 10
Sacred to the memory of Patrick Cowley of Knock Bane who departed this life the 25th of March 1845 aged ...... years
Also of Jane wife of the above who died June 14th 1877 aged 77 years
There are 6 Cowley stones in this section all in a row and mostly of Knockbane, if you and/or others are interested.
DJD

Ann Cowley nee Colvin/Calvin
died around 1842 according to the IGI
but I can't find a match on Brians site
also Patrick Cowley died somewhere between
1841 & 1851
In 1841 they were both living in Onchan he was aged 60 she was 75
The only match for him on Brians site is one aged 66 in 1845 in Michael