Is a bad relationship with the female guardian considered disobedience (ʿuqūq) for an individual of unknown parentage who was raised under her guardianship?

You must treat this woman with kindness and reciprocate her good deeds, especially if she breastfed you, for she is like a mother. You must treat her with kindness within the bounds of the Sharia, provided it is not permissible to claim lineage from her or to be in seclusion with her if she is not a mahram.