This question is based on SO THE PATH DOES NOT DIE. Fina's insistence on supporting her sister Isa, despite Cammy's protest, stems from:

In So the Path Does Not Die, Fina's determination to support her sister Isa, even when Cammy protests, is rooted in African communal values. In many West African societies, the family unit extends well beyond the nuclear household, and kinship ties carry binding obligations. A sister's need is not something one weighs against personal convenience; it is a duty that the community expects to be honoured.

Fina's actions reflect the communal ethic that an individual's identity is inseparable from the welfare of her relatives and community. She does not act out of political ideology (there is no political agenda behind her support), feminist ideology (the motivation is kinship obligation, not a gendered power struggle), or religious guilt (no spiritual transgression drives her decision). Her insistence flows naturally from the deeply held cultural principle that family members stand by one another unconditionally.