Hi,A.! :)
When my oldest (who is 16) started talking, he was using single words like "mama" or "gammie" (which became Grammy, my grandmother), "cup" and "milk", etc. sometime around 13 or 14 months or so (maybe earlier? I can't remember exactly when, now). But when he was 15 months old, over the 4th of July that year, I asked him if he wanted out of his high chair because he was acting like it. He just looked at me and said..."not really" and continued to play! I thought I was hearing things, but thankfully, both my mom and my best friend were in the room and they heard it, too! He was talking in full sentences by the time he turned 2 the following April. His brother, on the other hand, is 2 1/2 now, and has a limited vocabulary (caused by a developmental disorder).
Initially, your daughter's language will be made up of what we call "babbling", (and that will begin to occur around 9-10 months, maybe a little earlier or later). You can do things like point to something and say what that thing is...light, puppy, kitty, bug, mommy, daddy,grandma, grandpa, bottle, etc. and encourage her to repeat what you say.
The best thing you can do for your daughter's speech development is to use "real" words instead of "baby talk" ~ ie, say "blanket" instead of "bankie", or "bottle" instead of "baba". This is because if your daughter continually hears the "baby talk", she will think that is Language, and that is what she will be using as her words. That is not to say that you can't "make up" words as you play. Both my boys LOVE Dr Seuss books, and they are full of "made up" words!
Congratulations on your baby girl! It sounds like you're doing a fantastic job with her! :)
Warm fuzzies!
~J.~