Legally you are entiltled to vote for whomever you wish, however your family seems hell bent on getting your vote. Now taking a stand against this would be very bold and would have to give you kudos.

I also happen to live in BC and have some thoughts...
You can do early voting at your designated voting center prior to the actual election. Your voting card tells you when and where this happens. I recommend you do that.

Just be like i want to go and vote by myself to learn the whole process...how else will you learn? and just tell them you voted conserv..it'll make things easier in the long run.