Welcome to the joys of parenthood!
It's really not a big deal (I say that after having 4 kids, but I wouldn't have said it with the first one). With the first child, we tend to over react to everything, but then the more we have, we just say, "Oh, that's good ruffage!" JK.
But really, all little ones experiment with taste, texture, smell, etc... It is very normal. When you see it happening, simply go over to her and state, "Wow, that sure is dirty, next time, let's not put that in your mouth because its not good for your tummy, ok?" Soon she will catch on to what is good and what is bad for her.
A friend of mine caught her little one chewing on a cigarette butt while they were out somewhere and she just about got sick seeing it in her daughters mouth.
During this time, you will just need to keep an extra eye or two on her to teach her what is good/bad for her.
Take Care,
T.