Yes, that's certainly strange. There is no doubt that "my Daughter Elinor wife of Thomas Goldsmith" was the daughter of Ann Skillicorn otherwise Quayle wife of Philip Skillicorn in her will.
Unless she was her step-mother but having brought her up considered her to be her daughter. There was also a son James mentioned by his father but not on the IGI.

Yes - you are spot-on!

www.iomfhs.im/lawsons/twill/1814_017.html
Submitted by: Lois Ralph
Date: 21 February 2005
Original: LDS: 0106239

1 Lonan
The last Will and Testament of Ann Skillicorn alias Cannan — who after
recomending her Soul to God who gave it and her Body to burrial in a decent
Christian manner — disposed of her worldly goods and Effects in the
following manner
Item I leave and bequeathe unto each of my children viz Elenor and James
five pounds not to be laid out towards their Education by my Exor Together
with the whole of my wareing apparal and a piece of Linsey woolsey now spun
to be equally divided between them
Item I leave and bequeath unto each and every person having a right to
claim in my will six pence a piece
Lastly Item I Ordain Constitute and appoint my loving Husband Philip
Skillicorn my whole and sole Executor and residuary Legatee of all my goods
Chattles Credits and Effects whether moveable and immoveable and revoking
all others and acknowledging this to be my last will and Testament in
presence of these witnesses
KK Lonan
20 Dec 1813
Witness present
Margret Clague her X mark
Isabella Cannan her X mark Jur

At a Chapter Court holden in Douglas the 8th June 1814
The exor is sworn in court in form of Law & also as guardian & supervisor
of the children under age, and hath given pledges for the payment of Debts
and legacies namely Xtopher Karran and John Kelly both of KK Lonan
Probatum est
Thos Cubbon

Sue