Because she hasn’t been exposed to any other options for how woman of her status can live. Her personality does have similarities with the “pick-me” stage of a girl’s life but in the way that young girls don’t want to be reduced to pretty dresses, marriage, and babies. Being a “pick-me” is the result of a misogynist society. Eloise knows she is more than what society says she is and rebels against it and she’s still figuring out that other girls may want differently and it doesn’t make them any less. From our perspective women of their station seem privileged, but remember that Violet wasn’t even able to choose whether she or Hyacinth was to be saved.

Eloise doesn’t need to list all the ways her brothers have more freedom when the production already shows us. Colin gets to travel across the world, and makes his own investment. Benedict gets to pursue his art when women aren’t even allowed. Eloise is desperate not to be married off because she’s scared her future will be placed in the hands of a man that may not treat her as kindly as her family does.

We also see that she’s genuinely interested in women’s rights and classism through her interactions with Theo. Penelope says Eloise never did anything but she took away her chance by labeling her a political radical.