A Day passed since Last Egghead Chapter, so She should be there indeed.
Logically, whoever Devon is Impersonating got Captured, meaning They were Alone in Chapter 1078.
Only ones who could have had a Time Alone are Zoro, Usopp, Lilith, Franky, Kaku, Stussy, Jinbe & Bonney.
However, Zoro's Swords & Fighting Style can't be Copied without others Noticing.
Also Franky was left Conscious when He got Petrified, so if Devon wanted to Replace Usopp or Lilith, They would need to replace Franky too, which is not an Option, Devon can only Replace One Character. So Usopp & Lilith are Cleared.
So apparently there are Four Options:
1. Stussy & Jinbe got Separated which allowed Devon & Laffitte to Surprise Attack one of them.
2. Kaku was Captured before He caught up with Zoro
3. Franky got Replaced cuz He simply was Defenseless & Alone
4. Bonney for same reason as Franky
First Option is Unlikely though, cuz Stussy & Jinbe had no reason to Split-Up, and both are Very Strong.
Second Option is also Unlikely, cuz it relies on BB Duo attacking Kaku who is near Zoro, which is Very Risky.
This leads me to One Conclusion, Catarina Devon replaced either Franky or Bonney.