By the time you read this, you'll have returned from your Scottish break. I hope you didn't get too drenched, windswept and bedraggled. The weather forecast isn't great.
The Mary Killey nee Callow you found in the 1800 will of Cath Callow als Christian also had me going for a while when I saw it a few days ago, but it didn't take too much digging to identify her as Mary Callow bap 17 May 1772 Ramsey, to William Callow and Catherine Christian. She married William Killey 2 Nov 1796 Maughold. Her father's 1811 will also mentions her.