It is almost certain that his sister Margaret became his father-in-law’s third wife.

Balfour Paul in his Ordinary of Scottish Arms, p. 184, gives a blazon for Ogilvie of Hardwoodmyres granted in 1778:

Argent on a pale sable a cross crosslet fitchée or surmounted of a lion passant guardant gules, crowned with an imperial crown proper.

Another one to order from the Lyon Office, to get the genealogy.  But not while he remains solely an in-law!
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