is your spouse a taiwanese citizen? Then, what you need is
(4) Other document that is sufficient to prove that the applicant is capable of supporting himself or herself or making a living.
It doesn’t need to be more than twice of the Monthly Minimum Wage promulgated by the Council of Labor Affairs.
And, the document can be of your Spouse, Parent(s)-in-laws, or Parent(s).
Article 16 of The Enforcement Rules of the Immigration Act
or
Article 15 of 入出國及移民法施行細則