Yeah, being nice to servants definitely helps. If you get the gifts from Mrs. White and Sayra and Ria, then that's a sign that you're on the right path. I didn't invite Sayra out either, so that's not required (though inviting her to the Onvu tournament certainly wouldn't hurt). I raised the rebels approval by like 1/4 of the bar in week six and part of that was pulling off a successful ball. The other big boost was my convo with Sayra, which happened automatically. Couldn't say why she opened up to me and not you :(
I think it's just saving Penelope and the Summit (following Katya's , yeah. I bet that the servant scene before Clarmont's week 1 date also influences it. I was romancing Clarmont on this play through, so maybe that gave me more opportunities too? Antagonizing Gisette during the opening scenes helps too, but I think that may be more counterproductive if you want her to agree to peace...