I'm coming up to 14 months for an onshore partner visa, and only got the request for a medical (first contact from a case officer) around 2 weeks ago. I've been told it should be granted before I leave for Xmas in England in November, so when mine's granted it should be between 14-15 months. I've heard 13 - 18 and 15 - 18 months both thrown around for onshore's lately. When I applied in August '12 I was told 6 - 9, then it jumped up to the 13 not long after. So YMMV, but I wouldn't be surprised if it's closer to the 18 by the time a decision is made on your partner's, if she applies now.