Is it permissible to name a daughter "Amira" after her deceased mother, who was divorced, despite the father's objection and his wife's instigation?

Obedience to one's father is not an absolute obligation; rather, it has conditions. If your father has no vested interest in your abandoning the name you chose, then his obedience is not obligatory, unless it is highly probable that he would be severely distressed. However, it is advisable to avoid that naming choice to prevent disputes and out of dutifulness to your father. If your stepmother strives to cause a rift, she is acting wrongly and committing a sin. Both of you should be keen to honor your father, even if he mistreats you, for Ibn Abbas (may Allah be pleased with him) said: "There is no Muslim who has two Muslim parents, and he serves them dutifully seeking Allah's reward, but Allah will open for him two doors [meaning: of Paradise]. And if he has only one, then one. And if he displeases one of them, Allah will not be pleased with him until that parent is pleased with him." It was asked, "Even if they wrong him?" He replied, "Even if they wrong him."