Thanks for those marriages Pat. The actual birth records I was looking at were under the surname Ward:

WARD, Annetta 15 Nov 1891 Douglas 937 WARD, William WALES/MC GREAVY, Catherine

WARD, Florence 15 Nov 1891 Douglas 937 WARD, William WALES/MC GREAVY, Catherine

WARD, Frances Mary 8 Jul 1893 Douglas 1039 WARD, William WALES/MC GREAVEY, Catherin

So presumably Catherine McGreavey married William Wales in 1885 and William Ward in 1890.
There is a William Wales aged 28 being buried in 1888. So this would make sense.