Picking a handgun is a very personal thing and certainly not a choice that total strangers can make. When people say a handgun for a lady, most people automatically assume they need something small, light, and with little recoil but such is not always the case. I have personally known women that, with proper instruction, could handle large, heavy, hard recoiling handguns up to and including .44 Magnum without issues.
That being said, there are a couple of platforms that are, in my experience, very easy to shoot well even for inexperienced people. As has been mentioned several times, a S&W K-Frame or comparable revolver in .38 Special seems to be universally easy to handle. The grip of the K-Frame seems to fit a wide variety of hand shapes and sizes and the weight of the gun dampens recoil well without being so heavy as to feel unwieldy or cumbersome. Good models to look for include the S&W Models 10, 13, 15, 19, 64, 65, and 67 or a Ruger Security Six, Speed Six, or Police Service Six (some of the aforementioned revolvers are chambered for .357 Magnum, but they will shoot .38 Special ammunition just fine).
If a semi-auto is more to your liking, a full-sized 9mm will be easy for most people to shoot. Much like the S&W revolver, weight is your friend when it comes to recoil and a 30+ oz handgun dampens the recoil of a 9mm quite well. Good models to look at include the S&W 5906, CZ-75, Sig P226, Beretta 92-series, Stoeger Cougar, Browning Hi-Power, or one of the various 9mm 1911's. Polymer-frame guns like the Glock 17, HK USP, Ruger SR9, Beretta PX4, S&W M&P, and Walther P99 can also be good choices, but their lighter weight will come at the price of somewhat increased recoil. Be careful, however, when selecting a 9mm as most full-sized 9mm's on the market today are double-stacks and may not fit a person with small hands well.