In case anyone in the future wants to know: I had decent friendship with Jarrod and Gisette because I was trying to legendary with my WidowMC, realized that I forgot a Rebel approval point by not choosing the right summit goal before the Matchmaker. So I decided eff it, Gisette romance time! You have to choose the poltiical marriage route for that Then obviously romance Gisette. I had a perfect aquit in the trial and hit a lot of soften Gisette flags, but not sure if that matters. You can be compassionate and noble, but need to tank your ethics by week 6. Being a widow/courtier/princess and choosing death in your personal quests may help.
In my playthrough, I saved before the matchmaker (so I could go back and romance Emmett) and then decided to kill in my widow's personal questline to tank my ethics. In week 6, after doing the 3 scenes (if your manipulation isn't high enough for the check, you gotta let Jarrod kill the poor bird), you'll know you're on the right path if by the fourth scene, instead of seeing the political marriage candidates, Gisette approaches you and you two can conspire to marry Jarrod. If your ethics are low enough, she will go, 'Wait. Nvm. You'll do juuuuust fine bby.'
When talking to your political matches, Jarrod is going to be all grumpy about things. That's fine. Whatever. Just make sure when given the option, you select the 'you both ' (I forget the exact wording). Jarrod intrigued. Any other option is just a political marriage with Jarrod (but you at least survive). In my playthrough I found out about the rebels in week 5 and sold them out to Gisette. (I didn't get the Sayra confession scene). That makes Gisette bby very happy. Side with the royals during the negotiations. Then sit back and enjoy the banter and how Jarrod is actually kinda cute if Gisette makes sure he stays in line and doesn't hurt her beloved MC.