Well, I think one difference is that Jennette is actually a young girl where Athy has the mind of a grown woman. Jennette was also sheltered and has never worked a day in her life. Her life is about not asking questions and being a cute girl that everyone loves.
Athy lived in her other life as a woman who worked herself to death. She was an orphan and her life was about working through the many setbacks in her life. She is far more likable as a character because she is much more relatable. She had to develop herself and she only learned to act cute to survive under Claude. She knows how to be real. Jennette doesn't.
Even though Jennette is like 14 (or 15?) she has the maturity of a twelve year old to me. She's very innocent and just goes with the flow. This passivity makes it hard to root for her.
I think Jennette sees Claude and Athy as her ticket out of her life with the Whitey clan. At the Whitey estate she is barely allowed out. She couldn't even go to her aunt's funeral. For her it's like she lives in a gilded cage.
The reason its hard to find her interesting is because she is a bland character. Not bad, but not interesting. She just wants to go from a not bad situation to a little better one.
I hope that maybe in the future Jennette will actually become a more interesting character. Right now the last few chapters have focused mostly on her and Athy is just hanging around. However, Jennette can't compare to Athy whose is several times more interesting.
I'm sorry but no matter how hard I try, I cannot like Jennette(Is that how you spell her name? Coz like I don't know?). I know she isn't a bad character but I just keep remembering how she didn't do anything for our dear Athy in 'The Lovely Princess' book when Claude hated her! And now, Athy might be in danger because of Jennette! I cannot accept this because Claude isn't her fricking FATHER FOR GOD'S SAKE!!! I wanna go in there a scream in Jennette's ear that she has the wrong person as her father! And that she shouldn't be at all expecting that she is part of the father and daughter relationship between Athy and Claude! No, no, no, NO!!! Athy has worked way too hard! Ugh!!!