If it's their interior/exterior of their home and also if one of their homes is more cluttered with stuff you regret gifting to them.
Or their designs and which ones you feel strongest or most undecided against getting rid of.
If it helps, what’s your distribution of hobbies? Nana and Daisy are education, Lolly is music, and Flurry is nature. Based on that alone I’d say Nana or Daisy since they’re repeats.
I also was thinking between Nana and Daisy since they have the same hobby. I've never had Daisy, but I've had Nana in both New Leaf and New Horizons, and she's such a sweet girl. She's one that moved out before I got her picture and I kind of regret it, but I had too many normal villagers as well. That's why I settled on voting for Daisy.
I had to vote Daisy. She's cute, but not very interesting, in my opinion. Goldie has a similar design, the same personality, and is automatically better than Daisy because her name is a pun. (Goldie = Golden Retriever)
honestly, it all depends on who you’re okay with having move out; personally, i would go with nana as she’s my least favourite of your options but it’s 100% up to you! good luck.