Oops, I forgot to mention in this thread, SPOILERS for the Revaire plot, weeks 6 & 7 and ending possibilities!
Selling out yes, it's the option to ally with them or to go for peace that doesn't show up unless you've spoken with her!
IIRC the options you can get are:
- Choose to side with the royals (shows up even if you've promised to help Sayra, you can trick and betray her!)
- Of course you must side with Gisette (if you're on her romance route)
- Of course you must side with Jarrod (if you're on his romance route OR politically marrying him, which might be a bug? I have had both Gisette & Jarrod options show up at the same time)
- Refuse to take part in this at all (Gisette does not take that very well)
- Choose to side with the rebels (if you've promised to help Sayra; this can involve tricking Gisette with fake information, which is super cool and an achievement IIRC)
- There must be an option that pleases everyone (if you've convinced Sayra to try for peace; this involves trying to convince Gisette to go for peace too)
(I've not seen a special option for Clarmont, but I only played his route once and said I'd stay out of it iirc.) (... And then betrayed him to Gisette out of curiosity. It was horrible. :) )
All of these only require knowing about the Rebels' existence from the secrets chain, but it's possible to have that without having Sayra's relationship high enough to get her conversations.