(((Hugs))), ladies and welcome to BW!
Those long NWs are so exhausting! pumpkin_pie, please feel free to start your own thread if you'd like specific advice for your LO.
ChocolateyClaire, it sounds to me like you're dealing with the 3-2 nap switch. Have a read through this and let me know what you think...
All about the 3-2 transition- 5/6 months. I think if I were you, I'd start pushing that afternoon nap out to 1:15-1:30 and see if you can get it a little longer and phase out the CN. You may need to offer an earlier BT for a bit or if the CN is still needed AP it in the stroller or car, rather than fighting for it.
As for the dummy prop, she's about at the age she can start replugging herself. If you don't want to get rid of it, I'd start working on teaching her how to do this during the daytime and then start guiding her hand to it at NWs, eventually having her get it herself.
Six months can be a time of big change for lots of babies. There is often a growth spurt, wonder week, and new developmental milestones. Have you tried feeding right away at the NW to see if it makes a difference? I know you mentioned he doesn't seem hungry first thing, so that may not be the case. Is she working on new skills lately... rolling, crawling, etc that might be interrupting sleep? What types of solids is she having? Have you been offering them for awhile? I was thinking that refusing the dummy might be some sort of teething/tummy discomfort, but not necessarily.