Is it permissible to divorce a new Muslim wife who does not observe prayer, fasting, or Islamic dress, despite her affirmation of Islam and not denying the obligatory duties, but she fears fasting and justifies her lack of commitment by saying that she is still in the early stages of Islam?

It is recommended not to divorce the wife if there is a fear of her returning to her previous religion, unless her reform is impossible and she refuses to adhere to the Sharia rulings. In that case, there is no sin in divorcing her. You should try to teach her and encourage her to commit to prayer and hijab, while reminding her of the punishment for disobedience. If she responds, even partially, then continue your attempts to achieve her salvation from the Hellfire.