Guys in bike shops often tend to think all women need hybrids because they are not 'serious riders' enough to be on road bikes, or some such cliche. And sometimes it's true, some of their women customers are new hesitant riders who might feel more comfy on hybrids --especially if they do not do long rides.

But if you are always going to be on paved roads and aim to ride over 30 miles at a time- I'd say definitely go for a road bike. Or a touring/road bike. A road bike will feel very odd to you after riding a mtn bike, but you will get used to it quickly. Important to get a frame that fits you to start out though. Go to a bike shop that does thorough fittings of the bikes they sell.