Since I’m in love with Pepa now, please take some headcanons:
The same way that Isabela is the golden child of the present generation, Julieta was the golden child of the previous, because her Gift was the tamest and most immediately helpful of the three siblings’. This resulted in Pepa and Bruno growing especially close as children while Julieta carried the favor of their mother.
Originally, Pepa’s Gift more directly affected the weather over the entire encanto. But as the village grew, they and Alma began to demand that the weather occur on their terms in order for the land to be maintained as a paradise, which Pepa could not easily control with her power being tied to her emotions. Over time, Pepa learned to contain her Gift so that it mostly manifested around herself, which technically made her less useful to the village as a whole, but at least limited her tendency to disturb them.
She brushed Felix off for months when he first started showing interest in her, because she feared that her Gift would push him away if she let herself feel any strong emotions for him. But the first time she created a thunderstorm above their heads, Felix was amazed. He danced in her rain. And she fell in love with him that moment, creating a brilliant rainbow that stretched across the entire encanto. He was the first person outside of her siblings that accepted her fully for her Gift.
Pregnancy was miserable for Pepa, mostly due to the emotional toll. But Bruno often tried to reassure her by sharing visions about how awesome her kids would be.
Of all her nieces, Pepa is closest to Isabela. As a little girl, Isabela was drawn to Pepa and often asked her to water the flowers she grew. Isabela also loved to braid flowers into Pepa’s hair.
After Mirabel didn’t receive a Gift, Alma started pressuring her daughters, both 40 at the time, to try for another child, so that the family could prove the magic was still strong as ever. She pushed this mostly on Pepa, out of concern that another kid from Julieta would be denied a gift again. Pepa, eventually, complied, and later got pregnant with Antonio. Secretly, she was happy that she was the daughter holding Alma’s favor this time, though she’d never admit it.
Pepa often meditates in her room when she has alone time.
