I inherited a .32 S&W revolver. That got me talking to friends that I knew had interest in firearms and I tagged along to the range with two of them. Between them, they brought 8 handguns. A mix of pistols and revolvers. I shot them all. .22, .380, 9mm, 38 special, .357, .40 and .45. A good mix.
When I fired the XD9 I knew I'd found what I was looking for. It fit my hand so well and I found it very easy to shoot accurately. I went out and bought the XDM in 9mm. I've put 200 rounds through it so far in two trips to the range.
If you have friends that will let you shoot, I would recommend doing that from my personal experience. Actually shooting, in combination with the advice you've gotten here regarding what do you want to do with the gun, will get you what's best for you IMO.
It's been touched on, but availability of ammo is a consideration. I've had no problems finding 9mm ammo, but from other discussions here it seems to vary across the country. For example, .380 is nearly impossible to find here. If you don't have ammo, all the gun is good for is to throw it at somebody.
I took my wife to the range on my second trip and she shot for the first time ever. She liked it. She's better than I am. She shot the .32 also and didn't like it. I concur. I intend to trade that gun in on something for her. I'm researching now. She had problems pulling the slide back on the XDM and a revolver might be a better choice for her.
My other consideration is if one or both of us will ever want to carry. I don't want to budget a lot of money for firearms, so I'm trying to decide if we should get her something small that could be carried.