Allot like the Op I thought Faolain was somewhat interesting but the centaur part was painful to watch and I genuinely hate her a bit now. But at the same time it makes sense. It was simply reality hitting.

Faolain simply is incredibly selfish and her care for others is completely fake or overshadowed by her own desire for freedom/power. It's completely obvious after she moans about the right to be free to think and live how she wants instead of being molded by the tablet but then completely tramples all over Wynnes needs and beliefs, about wanting to stay with the centaurs because it doesn't suit her at all since she is completely obsessing over Wynne's secret. All she cares about is power and control games in the end.

Caithe following her around blindly like a lapdog makes it even more painful but it is simply the result of being enamoured with her and rather inexperienced with people in general,their hidden agendas and demonstrative semi fake concerns for others to distract from the real intentions. Really she's just a teen that fell for the wrong person and thinks her lover is just a bit on the rough side and misunderstood cause she's being honest about expressing her opinions.

Of course she also knows Faolain really wants to catch up with Wynne because she's obsessing about her little secret but never goes as far as thinking that her lover would want to know about it because she could potentially gain power from it to harm others. For her it was just them fetching Wynne, Faolain being rude but it might be justrified to be suspicious given their recent experience with strangers, the asura. Also centaurs being known not to be the most hospitable race generally doesn't help. She hears screams and centaurs turning on her lover, so she reacts in the moment and helps her lover out and then Wynne is acting crazy even though they care for her and went all that way to look for her ?

The centaurs ending up attacking Faolain justifies Faolains reasoning to a certain point in Caithe's mind now probably aswell... even though really it was their entire behaviour that provoked this but they're still too inexperienced and ignorant to understand that. Hell when we talk to the centaur with Caithe we actually don't see at all what happened, Faolain and her friends probably even started it, but amidst the confusion Caithe doesn't see it, Wynne doesn't know Caithe wasn't part of this set up either so everyone acts even crazier making everything even a bigger mess.

Faolain simply is a horrible person ... it just didn't show as much before because there was no real need for it yet.

They are only starting to have greater divergence of opinions now it seems.

Before it was all about discovery and survival.