To be honest, she doesn't really have a choice to "leave" the Emperor. This is why I can't really blame her for the ending.
After Rosemond is executed she requests he divorce and dethrones her - he refuses.
she requests he at least let her live far away from the palace - he refuses.
So she stuck between a rock and a hard place. She chose to make the best of a bad situation and Lucio did whatever he could to prove his worth to her. Also, she was dedicated to role and duty as empress of the nation which she very good at.
She's terrific. Her hatred and desire to save her family was justified. She didn't know all his trauma and abuse and self-loathing. The guy is a product of two abusive women and an apprently useless set of relatives/father/etc.
Her helping him and softening is a sign of good character, not weakness. She knows the real person behind her family's desmise is Rosamund manipulating a damaged man.
Indeed, this is why I find her even more beautiful and admirable as a character. I'm perfectly content with her hating him and letting him know her feelings as well. He does deserve her rage for what he's done to her (although he isn't aware of the past timeline, he's done enough in the present time to justify her hatred).
It takes REAL STRENGTH to lend out a hand to someone you hate when they're most vulnerable, miserable. She understands what's happening to him isn't his fault at all, no one deserves what he went through. Even if it's pity or sympathy, she acts in the best way someone could towards Lucio. I respect her very much and I'd love to become someone who is able to be as just and kind as her.
My comment wasn't really treading towards that in particular (I did read this spoiler in the novel forum). I'm speaking more of the present time where she's still the empress for her family's honor and to take revenge on Rosemund for the past timeline.
I'm unsure of what exactly happens after Rosemund is executed, but I do believe we've been told time and time again it wouldn't be easy anyway for her to abdicate due to the law or something along those lines... I do want to see Lucio's redemption and judge for myself (but at this point in time I don't wish for them to be endgame although I know they are).
I actually love Patrizia as a character, not only for her strength and beauty but because she has always been just.
I've seen some ppl complaining about her being 'kind' to the emperor, but I'm actually happy that she's willing to help someone in need whoever that is. Leaving everything aside, the Emperor never had a single person that could aid with his mental disorders (especially when he is having his attacks and seizures). NO ONE deserves to be in such pain and trauma without a single person reaching out to them, no matter who that is. I'm glad he seems to be moving in a positive manner and that he's slowly healing, he deserves that for his own peace of mind.