Sure she mayn't have lied about her age?? This seems the only possibility if the details make sense to you -

Dwelling: 16 Henrietta Balmoral Cot
Census Place: Kilmarnock, Ayr, Scotland
Source: FHL Film 0203602 GRO Ref Volume 597 EnumDist 22 Page 13
Marr Age Sex Birthplace
Robert DOUGLAS M 38 M Dingwall, Ross and Cromarty, Scotland
Rel: Head
Occ: Restaurant Keeper
Elizabeth DOUGLAS M 32 F England
Rel: Wife
Jane DOUGLAS 11 F Kilmarnock, Ayr, Scotland
Rel: Daur
Occ: Scholar
Alice DOUGLAS 10 F Kilmarnock, Ayr, Scotland
Rel: Daur
Occ: Scholar
Elizabeth DOUGLAS 9 F Kilmarnock, Ayr, Scotland
Rel: Daur
Occ: Scholar
Robert DOUGLAS 5 M Kilmarnock, Ayr, Scotland
Rel: Son
Occ: Scholar
Annie DOUGLAS 3 F Kilmarnock, Ayr, Scotland
Rel: Daur
Alexandra DOUGLAS 1 F Kilmarnock, Ayr, Scotland
Rel: Daur
Marion MC KINLAY U 18 F Ireland
Rel: Servt
Occ: Gen Servt Domestic
Mary BURNS U 19 F Dalry, Ayr, Scotland
Rel: Servt
Occ: Gen Servt Domestic
Louisa MC GLASHAN U 26 F England
Rel: Visitor