Is marriage predestined, and does a female receive what God has decreed for her without change, and is supplication (du'a') inscribed in the Preserved Tablet such that a servant supplicates only if God wills it?

Everything that happens to a servant is predetermined and inscribed in the Preserved Tablet. Allah wrote the destinies of all creation fifty thousand years before He created the heavens and the earth. A servant has no knowledge of the unseen, and he must strive to employ permissible means. Supplication is among the most beneficial means, and it is itself part of Allah's decree. Indeed, it is from divine decree that affliction is repelled by supplication.