.40 is one of the worst for brand new gun owners, women in particular. Everyone has a cop friend that will tell you to buy a .40. .40 is most difficult to handle recoil of the three major semi-auto calibers. It's also expensive and hard to find ammo.
I would suggest an M&P 9mm full size. I'm partial to them, but for good reason. I think they're the most ergonomic of the "big three" and probably only second or third among all polymer pistols. Interchangeable back straps are nice, although most everyone offers that nowadays. I think it shoots soft, the trigger is decent out of the box.
Now everyone will chime in and say that 9mm is too sissy. It wouldn't stop anyone. Blah, blah, blah. With good ammo 9mm can be equally as effective as .45. If I can deliver 9mm rounds accurately, quicker than .45... I don't see a handicap here. I don't have anything against .45. I have one for my secondary home defense, above a 9mm. But for someone looking to get their first pistol, my recommendation is always 9mm.
You can't really go wrong with any of the big three, being Glock, Springfield, and S&W. Walther's PPQ is pretty nice. H&K P30/L is about the cream of the crop for polymer semis. Sig's P226 is the flagship of their line. Carried by SEALs currently I believe.
My two pennies.
