But like, Madoka consistently defines herself specifically through her relation (Si) to other people (Fe). She doesn't develop an identity of who she is on her own, like Sayaka who is the clearest Fi user, but devotes her energy to thinking about how to be acceptable to others, how to find an agreed place for herself, and in the end is happy and ready to claim a place defined by her service to entire peoples. It's Fe, Fe, Fe. She defines her individual self-hood as part of a greater collection of people. Her ultimate happiness is based on accepting the values of everyone instead of defining her own.
She's especially an Si dom in the regard that she's so sensitive to how she fits with others, what she can do and contribute, but more so specifically wanting to be someone who fits and contributes and fulfills a duty or service. Her compulsion to see herself as just one part of the group/community/et cetera is far too strong to be tertiary Si like an INFP, and too rooted in the collective to be individualistic Fi.