I don't think this is allowed, although I have seen users transfer points to another member (besides their spouse, which is allowed). See another older post at Re: Selling my marriot points.
You can either earn the additional points to reach 12K or buy it from Marriott.
You can buy points from Marriott, but not another rewards member. Sorry. See here for the info on buying points:
Scroll down the page to 'BUYING POINTS'.
I'm sure the Community Manager will chime in here.