Agnes Aikman was a sister to my 5th great-grandfather, Alexander Aikman. I do know that Sam Niblak, Agnes' husband, was an overseer of local roads in Mendham in 1763-64. He had land in Mendham in 1755 and 1760. He was listed as the owner of some stray cattle on several occasions.
I did hear from a Niblak descendant at one time - will try to find that info and send it on to you.