Some years ago I had the same situation -- my wife could not touch the ground with the GG 300 vertical. We first tried the lowering links and raised the forks in the triple clamps. That helped about an inch or so. Did not try lower profile tires or shaving the seat, those would help I think, in terms of lowering the bike.
One related "fact" to deal with is rider weight. Ofter shorter riders weigh less than the weight the stock fork and shock springs are set up for. So even if one lowers the bike sufficiently, there is the problem of whether the fork and shock springs are correct for lighter weight riders, so the suspension works right for them.
After a year or two, we took our forks and shock to a suspension tuner (Les at LTRacing, well known to this forum) with instructions to put the correct springs in the forks and shock, and "shorten" them to achieve a 1" seat height drop. This turned out to be a very good decision -- Les did a very good job, well worth the money, we could not be happier with his work. Only downside is the skid plate is lower, but that is a price one has to pay no matter what, so shorter riders can touch the ground. She is very satisfied, the suspension works great. Were I you, I'd send the forks and shock in to be lowered, but that's an individual choice.
Not sure you can shorten the forks and shock by 3". Maybe you can get 2" there (not sure), and another inch out by one of the other methods (tire profile, lowering link, raising forks in triple clamp, etc)? Good luck whatever you decide!
I think the price for "lowering" through Les will mainly be cost of custom springs... With a revalve - he doesn't charge that much for the service itself.
www.lt-racing.com
A lowering link isn't a great idea if it lowers by too much - it changes the linkage ratio curve by too great an amount....
A specific Q and A on suspension lowering can be found on Les' website here :
http://www.lt-racing.com/html/suspension_topics.html#SuspensionLowering
jeff