Is the wife obligated to obey her husband if he asks her to postpone conception for two years due to his concerns about their son, who has not yet spoken, and about his work situation?

If the spouses agree to temporarily postpone pregnancy to care for a particular child, there is no harm in that. However, if the wife does not consent, the husband may not force her to postpone, for procreation is a shared right. The Prophet, peace and blessings be upon him, forbade coitus interruptus with a free woman except with her permission, because she has a right to the child. As for postponing pregnancy due to fear of poverty, that is not permissible.