Mitchell/Lyon link

[Mitch1957]

Hi everyone. I am stumped on the following.
Cristian Mitchell born 1677 at Brechin.
George Mitchell born Jan 1679 at Brechin
Parents George Mitchell abt 1649 and Elspit Lyon born 1637 of Brechin.
The only records I can find about Elspit Lyon is she married a John Spence and that her parents are
Jon. Lyon and Elspit Watt.
But is listed on Scotlands people web site as having Cristian and George..
Now i am led to believe Jon. Lyon is the son of Sir Thomas Lyon Master of Glamis.
Please could you set me on the right track.
Regards
M.A.Mitchell (Tony)