i think too many people dismiss theo's role in eloise's story and make her be someone 100% against marriage and romantic love when that was never the case. her issue has always been w society and the marriage market being forced upon them, theo's there to highlight that. her connection and feelings for theo were real, she's clearly not against it but simply dont think she can find someone to truly love in the society they live (that's also why i think benophies gonna have a greater impact on her than in the books), and she's completely fine with that. eloise never wanted to marry, eloise doesnt want a love but not wanting is different than being opposed to it. and imo that opposition is what her arc has been about for the past seasons.
i also dont think the show is painting eloise in a bad light for this in specific, especially on s4. she's being left out by every family member and her own mother doesnt take her seriously. none of these scenes were shot in a way we would feel anything but pity for the way she's been treated. she's getting lonely, and it isnt her being a spinster that's causing it but the way people nearest to her are viewing her. however, i do think this all clashes w something else that's been there since s1: eloise seeing the problems of the marriage market but not seeing her mother or sisters as victims of it. for me it's a repetitive narrative that never seems to conclude, and that's why eloise's entire arc in the past seasons seem to go nowhere. but she is growing and they are setting a good foundation to not make her the victim of society she always feared. i think, above all, she's gonna find a best friend in sir phillip, someone unexpected that she meets and builds a connection on her own accord, outside of everyone's sights and expectations, including her own.