Why didn't filial piety, supplication (du'a), and charity (sadaqah) avail in making her marriage successful, and she is now considering divorce?

Filial piety is a right, not a favor, and one must not act condescendingly towards Allah regarding a good deed, for success in it comes from Him.

Marital problems are trials for a purpose, and Allah tests the righteous; everything Allah decrees for a believer is good for him.

The foundation of married life is religion and good character, and material differences do not prevent happiness. Love is not a prerequisite for the continuation of marriage, and kind treatment can engender affection.

Strive to keep away Satan, who seeks to cause separation between spouses.

The wife has rights over her husband, such as kind treatment and financial support, and a wife's assistance to her husband is a sign of her good character.