Is it permissible to work for a French company, despite the insults that have come from France against the Prophet, peace and blessings be upon him, knowing that the job is good, high-paying, and offers learning opportunities? And would this be considered a betrayal of the Prophet, peace and blessings be upon him, and a lack of support for the campaign to defend him?

You have done well in defending the Prophet, peace and blessings be upon him, and protecting Islam, for this is the duty of every Muslim. The answer to your question about work depends on whether it brings benefit and prevents harm, and comparing that to not working. If the work is permissible, with the estimation that its benefit outweighs its harm, then refer to the guidelines for women's work in Fatwa no. 51760.