S.H.
Well, we took my daughter there when she was 2 years old.
I don't know the area well, but there are not a lot of places to take a baby.
Many hotel areas are casinos, and for adults only.
Or, there is walking around.
Or sightseeing, the aquarium/zoos etc.
But at that age, a baby won't be really sightseeing... per say. Like an older child would.
Maybe there are kiddie shows there, I don't know.
Most of the kid venues... are for older kids.
But every State, has a Tourism website.
Just Google Search "Las Vegas tourism website."
Here is another good link about traveling there with a child:
http://www.vegas.com/traveltips/guide/familyvacation.html
http://govegas.about.com/od/familyfun/a/kidsinlv.htm
Bear in mind, that "You" will probably be the one, who minds her in Vegas... and in the stroller. While the others or whomever you are going with... goes to the Casinos. Where kids cannot go.
That is what I did, when we went with my daughter and my Husband and a friend joined us there. I didn't mind though.