Hi. Thank you for the reply.No you don't have to fill the Military form. because this form is to be filled by anyone included in application. as neither you nor your wife worked in military so no need to fill it. Plus i am principal applicant and my father also worked in military and we did not fill this form. Hope it helps.
But if we mention my wife's dad name in the application as a family member of the principal applicant. What if in future my wife wants to sponsor her father.? Won't it be an issue