These early Creech families are hard to sort out.

I believe Simon was born ca 1675, son of Robert mother as yet unknown.
Eldest brother Robert bp 4 Jun 1671, younest sister Joney bp 4 Feb 1680, both at Braddan.
Assuming Simon and 4 other siblings bp Braddan though not confirmed.

The youngest child, Joney, died unmarried but her Will gives us the names of her siblings.

Simon & Mary had five children, but his Will mentions only Robert & Alice. If Isobel was alive at his death why was she not mentioned?
If she did survive childhood I think she married William Killip in 1756 at Lonan.

I believe the Isabel that married John Quine was bp 16 Feb 1718 at Braddan, the daughter of Robert and unknown mother.

So far the only part of the John/Isabel Quine family I have followed is the third child, John, who married Margaret Clague. The fourth child was Thomas.