Hi-de-ho
The 1841 census at Ullapool has Roderick as a Weaver, with children;
Margaret born about 1829
Murdoch born about 1831
Janet born about 1833
Christian born about 1835
Kenneth born about 1838
Donald born 1841 (3 months old in 1841 census)
Looking at christenings in the Parish Register (I have photocopys of most pages) I see;
Margaret c. 7 October 1827, father Roderick a Tenant at Leckmelm
Murdo C. 15 July 1830, father Roderick a Weaver at Leckmelm
Janet c. 20 January 1833 at Corrie, father Roderick, occupation not given. Corrie is the farm between Leckmelm and Ullapool.
Though young Margaret's christening date looks early for the census, the age then might be wrong, or a first Margaret died young and a second named for her.
Roderick Stuart (surname spelling was variable in records then), above 30 years of age was noted as a Weaver, resident at Leckmelm, in the 1827 Militia List. Cannot see him in the 1826 list, however he is at Ullapool in 1825 under 30 years of age.
The marriage of Roderick Stewart to Christy MacKenzie is noted as 20 January, 1824, his residence as "Rhuairdacadhail", hers as Leckmelm. I do not think that first place is in Coigach, perhaps Gadget or some other poster might know it. The first syllable "Rhu" suggests it is a cape on the coast, second syllable "aird" I think meant a cape, next two syllables "acadh" refer to a field, aind the last syllable "ail" included to confuse non-Gaelic speakers like myself, har har.
Regardless, most likely within a generation or two before 1824, these Stewarts were at Badenscallie or Achiltibuie.
Donald.