Cw: This is a ramble of an autistic person who right now is in the bed while writting on her phone with no planning, this may not make sense.
I feel if Jacinthe and Lebanne's relationship was actually slavery then Jacinthe would not be really happy to help Lebanne to become stronger and Lebanne would not accept that help with a sweet smile in her face.
Like, think about it, the last thing a slave owner would want is their slave being free of themselfs.
So, its pretty much implied the promise of Lebanne of being the maid of Jacinthe will finish once she defeats Jacinthe in a fair fight, and not only that, she WANTS to defeat Jacinthe, its almost a goal in her life, if you wanna call it that way.
And we know Lebanne frustration with Jacinthe is not actually a hate towards Jacinthe (the whole dancing thing tells me Lebanne does care for Jacinthe. Leaving my ship behind, i do feel they are friends) , she is actually mad at HERSELF, because she cant defeat Jacinthe no matter what she does.
(You would think "this means she wants to defeat her so she can leave Jacinthe" but i dont think so, or well, at this point that is not her main goal, i feel this is more of a pride thing, Lebanne is a figther, if she cant defeat Jacinthe, then that means she needs to become stronger.)
And we know this is not Lebanne trying to make Jacinthe happy, because she does not hesite to tell this to Jacinthe.
These are her feelings and she feels comfortable enough to share them with Jacinthe.
And so, if Jacinthe was a slave owner, i feel she would shut Lebanne down, she would NEVER allow her to battle, to make her as weak as possible.
But she does not do this.
"As before" implies they train very often, unless my english is failing haha.
And Lebanne accepts this with a gentle smile in her face
To add to this, we know the punishment Jacinthe gives to Lebanne for fucking up (im gonna be so fr here, Jacinthe was rightfully mad a Lebanne in the dlc lol) is fighting with Jacinthe A LOT.
So we know Lebanne and Jacinthe battle a lot, and we also know Lebanne battles a lot in the SBC
(Tho after this Lebanne says "What?" But i dont know if this is Lebanne being surprise bc Jacinthe is intergecting or if this is false and Jacinthe is just jealous 😭)
But then, what do we do with this dialogues?
Well, of course, this is not a "i never battle", to me this is a "FINALLY not a battle with rich people / someone i cant never defeat"
We know Lebanne was a street figther, she used both her pokemon AND her fists, so the SBC battles are not her thing and she is just unable to win against Jacinthe, so a battle with the protagonist is something different, something cool.
But does this mean Lebanne wants to leave Jacinthe? Nope, or well at least i feel she is not only doing this bc of that.
Because Lebanne WANTS, NEEDS to defeat Jacinthe, its her new life goal (i would put a picture but ahh 10 pics limit) so if she leaves, then she would not be able to do this.
AND lets remenber Lebanne was the one who made the promise / agreed to the bet.
And i feel its more "SHE made the promise" because Marcia is there and it seems Lebanne made a very similar promise to her.
And we know how prideful Lebanne is with her promises, because when she tells to Marcia she cant be her partner, she says with a sad face "that is a promise i cant fullfil."
Lebanne is wild and savage, but she is also prideful and a woman of her words.
I could say a much more stuff but the 10 pics limit is annoying, but i think my whole point is that i feel Lebanne can leave whenever she wants but she just do not want to because she is prideful af
To me Lebanne and Jacinthe's relationship is like the one Ivor and Gwymm have (the game even compare them a lot), one is sane and the other is well meaning but very obnoxious with their goal, and while both care for each other, good god please communicate.
Edit: (Please, PLEASE correct me if im wrong in this, i feel i have watched enough dlc content of Jacinthe and Lebanne but still pls tell me if im wrong)
I feel the need to say we dont know much about Lebanne's maid job, we dont know if she gets paid and if she does how much does she get, if she has off day, etc.
For all we know, if she is getting paid, that could also be a huge thing of why she is staying, being the right hand of a very rich woman could get you a lot of money.
(sorry for a possible broke english, im mexican i talk spanish)