Wow... 3 months... or rather 11 weeks (minus a week for a taper)... to train for a half marathon and you have never been a runner? Hhhuuummmm.
Are you OK with walking the run? If so, then I say go for it, and train with a walk/run combo to prevent injury. Since you do not have a running base to start from... and there is the 10% more a week rule... you really don't want to ramp it up too quickly.
But if you do a walk/run combo... you can ramp up quicker as walking is easier on your body than running.
I would suggest trying a 5 minute walk/2 minute run combo for your longer sessions and run your shorter sessions. That way, you can keep your run fitness up for the walk/run sessions.
Hopefully Wahine will weigh in on this one. I'm not an expert... but I really don't know if you can go from no running base to running a full half marathon 11 weeks later. Again, just sounds like you would be asking for an injury. But you could walk/run it!
"Life is not a journey to the grave with the intention of arriving safely in a pretty and well preserved body, but rather, to skid in broadside thoroughly used-up, totally worn out, and loudly proclaiming: WOW WHAT A RIDE!!!!"