What is the ruling on a fiancée working as an architectural engineer, whose work sometimes requires her to leave the workplace, while her fiancé refuses this and only approves of her working inside the administration?

A woman's work must be governed by Sharia regulations, such as the absence of khalwa (private seclusion with a non-mahram) or prohibited mixing, not traveling without a mahram, and adhering to Islamic manners like not speaking or moving in a seductive manner, and not displaying her adornments (tabarruj). Her work must also not lead to neglecting the rights of her husband and children. If these regulations are met, then there is no objection to a woman working. If they are not met, then it is not permissible for her to work. A suitor's objection to her work would be valid if the woman violates the aforementioned regulations.