Cara had done most growing by 6 months - she added maybe another half inch in height after and 'filled out' between 6 and 9 months (mind you 'filling out' is hardly apropriate, she is quite a slim mini) I reckon Mo has half an inch of height MAX and may fill out a little more although she is already stockier than Cara. Mo is 7 months.
Dannie is right - 9months they are fully grown physically. Can take up to 2 years I'd say for them to reach 'adult' temperatment (adult used in the loosest possible sense of course)
Cara and Mo, two black mini's served by Elaine, the cook, poop picker, and chief toy thrower.
I live by the Mini Schnauzer code; when in danger or in doubt, run in circles, scream and shout!