When we dropped the DF we did get some early mornings issues. I was panicked about it, but it didn't last. When we got the dream feed down to 8 I did dropped it completely. How many ounces are you giving? Or how many minutes, if you are not doing the bottle?
It's not so much that 1h15 minutes is short, just that maybe not a complete nap, so maybe she can't do the 3 hours.
I hope the rest of the day ends well.