Are dummies really so bad? I don't think you should feel guilty - esp. if it's a source of comfort for her. Most kids I know stop using their dummy when they are ready. Sometimes it's a matter of, when they are getting too old for it, just not buying replacements. Their dummy soon gets old and they don't like it any more.
Gabby had a dummy on day 2 because all she wanted to do was suck. She doesn't have it all the time (and Daddy is more inclined to give it to her than I am) but I would rather her be dependent on that than screaming all the time or sucking her thumb.