I wouldn't mess with the day feeds at all, the dreamfeed is a bonus feed really and not all babies take it. Neither of my two took the DF at all, so we just fed them when they woke at night and were guided by them.
It could just be a phase so you can either stop offering it and see what she does or keep offering for a while. Providing you feed her when she tells you she is hungry, if she isn't waking for a feed she doesn't need it. Without the DF you may find she wakes again for the 3am feed.
Laura