Hi Don,
Not that I know of but I have a great interest in anyone with the name Frater or varients of it.
Its very interesting that you have a Isabella Frater/Fraiter I believe she may be a sister of my John Frater/Fraiter/Fratter who was born abt 1776 in Denholm,Cavers,Roxburgh and died 25 Feb 1838 Bulls Hugh, Selkirk. If this is the case fathers name is John Fraiter and mother unknown as yet. Frater is not really that popular of a name so when ever it crops up I like to see where it goes or comes from.
I have had a bit of a look in all the data I have on Frater's and can not find a marriage for your Charles and Isabella. How ever I did find the children you mentioned:
Robert Stewart b. 01/08/1811
John Stewart b. 14/03/1820
Margaret Stewart 14/07/1815
Isabel Stewart 07/10/1817
Elizabeth Stewart 05/12/1813
I also believe that Jean may be one of their children altho on the register is says Father Charles Stewart and Tibby Fraiter( I think that may be a misprint or misspelt or a nick name ) something to keep in mind anyways.
Jean Stewart 21/06/1823
The reason for my interest is that my surname is also Frater
Will be interesting to find a marriage for Charles and Isabella.
Warmest Regards
Christine