your first paragraph describes kisfps. infps are not asssertive. isfps are. assertiveness is Se. infps Se is their lowest/weakest function.

your 2nd paragraph also fits isfp. "low maintenance" = isfp is 1. an introvert (self-reliant) 2. Fi super high (Fi, vs Fe, is inexpressive, tries to solve their own problems themselves). otoh, "when she needs me SHE NEEDS ME" is fitting too because its Se; as you pointed out, she "demands" it - as i said, Se is assertive

isfp is as we can see wildly varied, even within the same person. mbti people (as opposed to jungian typology people) do not understand this because the mbti definition of Se is just... wrong.