Sophie, when it comes to cordless drills, one size does not fit all. How will the drill be used and how frequently? Is it going to lay in the utility room drawer most of the time, just coming out occasionally to hang pot racks and assemble childrens' birthday and Christmas gifts? The larger 18V drill would probably be overkill. The 18V ones are fairly heavy and the grip of a small woman might find it to be an ungainly size. However if this is going to be used frequently by a professional or serious do-it-yourselfer driving lag screws, then the 18V model would probably be fine. There are a wide range of cordless drills manufactured, serving various needs. Go down to your local Borg and check out the various ones on the shelf before you decide.