There's only one family with an Alexander McRae (not MacRae) as father in Eddrachilles 1841. His wife isn't Lucy though the name is down as Fairley McRae.
Marriage Familysearch
Alexander Mcrae marriage: 26 Feb 1822 Assynt,Sutherland,Scotland
spouse: Fairly Sinclair
SCT1841/49 Place: Eddrachilles -Sutherland Enumeration District: 5
Civil Parish: Eddrachillis Ecclesiastical Parish, Village or Island: -
MCRAE Alexr M 45 Tenant
MCRAE Fairley F 45
MCRAE William M 15
MCRAE Barbara F 10
MCRAE Duncan M 10
MCRAE Merian F 9
MCRAE Bell F 5
MCRAE Alexr M 4
All born Sutherland There may be older children as there's 4 years between marriage and Wm.