L.L.
If you don't want her becoming dependent on it, I'd suggest taking it away then! However there is nothing wrong with using a pacifier...my son loooooves his. He's 27 months old but at this age, can only use it when he's in his bed. We plan on getting rid of it very soon.
Anyway, if she likes it and it helps her sleep, I say let her use it. Happy, rested baby makes a happy, rested Momma. :)
Lynsey