1787: Richard Corkill - d 22 Nov 1786;late of Douglas, brewer;ch Thomas, Elizth, Cath (5s ea);wife Cath exex

I can't find the daughters baptisms - Elizth, Cath.
but did find Mary,

Richard Corkill and Kathrine Corrin

Richard Corkill:Marriage date:23 Jan 1720 :Braddan, Isle of Man
spouse:Kathrine Corrin
digital folder number:004494656

Thomas Corkill Christeningevent date:30 Apr 1723:Braddan, Isle of Man
father:Richard
digital folder number:004494656

Mary Corkel
christening: 03 Feb 1725 BRADDAN,ISLE OF MAN,ENGLAND
parents: Richd Corkel

The Braddan Parish Registers need to be searched.

the only Thomas Corkill Wills after the last child born in 1802 are -
CORKILL, Thomas1815 Braddan E 2 0106417
CORKILL, Thomas1816 Braddan E 2 0106418