There are two types of walkers: the roam free kind ( baby on the loose!) and the "stationary" kind where the baby can only go around a center post.
First, we'll look at the "roam free" breed.
Pro's: 1) babies LOVE these walkers! 2) They are pretty easy to transport from one room to another (in fact, baby will usually just follow you), 3) these are usually cheaper.
Cons: These walkers are dangerous. 1) Although they have special rubber blocks on them that will catch on the floor if the walker isn't level (as in, on its way down a flight of stairs) it isn't fool proof. You MUST MUST MUST be positive the baby cannot access a staircase. In a split level home, this is especially challenging. 2) kids can now reach stuff they couldn't before. If you think your home is kid proofed-think again now that walker is here. Kids can now reach table cloths, towels hanging off the oven handle (read: kid can open the oven if you don't have a lock), door handles, TV/stereo components, etc. You get my drift. All that stuff was out of reach when the kid was horizontal. 3) Some kids get used to being able zip around and will be SUPER frustrated at their lack of ability sans "suicide cart " as they are sometimes called (catchy knickname isn't it?) and some people think the walker can actually impede baby's progress towards independent bipedal locomotion.
" going nowhere fast" center post style:
Pro's: Safer than the "suicide cart" since baby can only go in circles, and therefore can't get near the stairs, door knobs, table cloths, floor lamps, etc. UNLESS you don't carefully consider the circumference of the walker's route AND your baby's "wingspan" Caution: it's bigger than you think.
Con's: 1) these are usually more expensive, because they come with all kinds of toys attached to them. 2) because of the design, they take up a lot of space (as in, your entire living room) and they are not typically easy to store, and are, well, stationary, so you can't take them to grandma's house. 3) Babies usually get bored fast. They want to GO places once they start to stand and " cruise" (walking holding onto stuff, and then going solo for short trips between furniture.) they get pretty upset about going around in circles.
My advice is to skip them both at this point. Your daughter is well on her way to walking on her own. Neither of these is going to help her (if that's what you were thinking) walk faster or with less falling down. She WILL fall pretty frequently, but believe me, most of the time she won't care at all.
I personally had the "suicide cart" variety, but I mainly used it for those times when I needed to have my "cruising" baby in the kitchen while I was cooking/cleaning and didn't want him pulling up on the kitchen chairs with no where to go. It got about a month of use, then he figured out how to climb out of it by hanging on to a door knob, or whatever, and pulling himself up until the center of gravity was high enough that when he leaned over he'd fall over and be free. Then , he'd shove the empty thing at his older brother'a block tower and make him cry. Be on the look out for that. :-)