Hello Philip,

I haven't been following the recent Looney messages because I am trying to get my Andreas families in some sort of order to post overseas for the FHS exhibition in Andreas next month. However, with a few of their wills sitting in front of me I can tell you about some grandparents' wills who did/didn't name grandchildren, although many of these will be earlier than the period you specified.
Your problem is trying to prove a negative. To be able to answer, people would need to know that the will was written by someone who had living but unmentioned grandchildren, which is not as easy as finding wills which name "my grandchild", so that you know he/she is a grandparent!

Joney CLEATER als CAIN 1736 names 4 daughters, daughter-in-law, and two sons, no grandchildren. Her husband John died the following year and names 3 of his daughters and his two sons. No grandchildren. When he died their eldest son Philip the heir had 3 sons, two of whom were alive when Joney died, and all three were still alive when their mother died the following year (1738).

In contrast John's father Philip Cleater (d.1716) "bequeathed his part of all ye Lands to his son Jon during his life, And then after his decease to return to his Grand-child Phillip, and then from Child to Child, in case ye sd Phillip shou'd dye Issuless, desiring his son John & his wife to give their consents here-unto, & settle their part of ye Land upon their son in like manner".
So he was interested in the land but otherwise mentioned only his two sons, and no other grandchildren. (Their mother died when the sons were underage.)

Mary CHRISTIAN d.1788 had a marvellous will, mentioning her 5 children. She left money to the illegitimate son of her dead daughter for "when he will go to a Master Trade". She mentioned her eldest daughter's 6 children, and her next daughter's husband and three daughters. No children of her two sons were mentioned, but not known whether they had any at the time (aged 29 & 26).

Charles JOUGHIN 1723 named his three remaining children and only one grandchild (of many). His son John predeceased him leaving 4 children, unmentioned by Charles.

Joney JOUGHIN als COWLE 1750 mentioned 4 children but none of their children.

Mary JOUGHIN als CLEATER 1756 mentioned all her children, her grandchild Anne, and her daughter Bahee's child, but not the others.

Ann JOUGHIN 1785 mentioned her husband, children, and one of their husbands (and another husband received his wife's legacy) but no grandchildren.

Not much of a sample, but on the whole I'd say that grandparents often mentioned grandchildren but less often by name than as a child's son/daughter, and it was unusual to name all of them. Of the ones I looked at only Mary Christian mentioned all her grandchildren, assuming her sons didn't have any.

In answer to your other question, I can't see any reason why they would mention a grandchild unless he/she was being left something? And obviously it would be drawing a pretty long bow to assume someone wasn't a grandparent because grandchildren weren't included in their will. You must have examples of all I have written in the wills you hold?

Sue