hello boxterspeed3, ok here's one option:
first after you land in canada, its up to you if you want to stay here for awhile or go back immediately to Philippines BUT your PR Card should be mailed to you back home(Phil.) by your parents if you're going to that, so that you can enter Canada anytime you want.
marry your girlfriend, and apply for spousal sponsorship, which should be done in Canada because you are going to pay for the fees worth $1040 for processing and landing fee.
processing time changes all the time, but for now according to CIC.GC.CA processing time for Philippines is 9months.
now, you are asking if she can work in Canada while processing her application, ok
question:
how can she come to Canada? unless she will enter Canada as tourist for this reason she can't work,because tourist are never allowed to work, if she will work thats illegal.
i don't know how are you planning to get your girlfriend and asking if she can work here while application is in process...in my opinion it is better and safer if she stay back home for awhile and wait for her VISA, no hassle its just the matter of time.
have patience, its no rush! good luck!