Anyone

U can get married anytime during the process, yes - till your PPR. However, once done, u'd be required to "declare" that before obtaining your PRV, submit her apps+docs+fees, await her meds, get the nod & fetch your PRVs together - before u board the flight.
It'd take a bit of time, usually about 5-6 months delay should be expected, but is the wisest course of action.
Married, but "land" w/out processing her apps - would be your death-knell.
Marrying as early possible, during the PR processing, would be ideal, 'coz then nothing much would have been completed on your own file.
Qorax