Hi - there is no option to search the 1921 Census using place of birth on Scotland's People.
There are 9 Annie Morris aged between 19-22 on the Census. Two have middle initials. Annie B and Annie R. One is an Annie Jane Morris.
I looked at the ref. no for each Annie Morris.
Then, searching the name Morris in each area for all 9 women - 6 of the Annie Morris appeared to be living with other people called Morris (they all shared the same ref).
Three, listed below, do not appear to be living with anyone called Morris.
Looby

MORRIS
ANNIE
1921
F
22
486/ 7/ 1
MUIRAVONSIDE
STIRLING
MORRIS
ANNIE
1921
F
22
644/18 45/ 21
POLLOKSHIELDS
LANARK
MORRIS
ANNIE
1921
F
21
168/1 9/ 1
ST NICHOLAS
ABERDEEN