Retired Senior Citizen As Joint Sponsor For K1

[AR&CB 2]

As it gets closer and closer to my fiancee's interview date I'm trying to make sure she is 100% prepared with everything she needs so she gets approved. One area of concern is the joint sponsor I am going to provide. I live in the very same household as my dad and he makes the required amount of money just from his pension for himself, myself, and my fiancee and if he also includes his social security retirement income his annual salary more then doubles the amount. Would it be ok with him as the joint sponsor even though he is a senior citizen that's retired? The appointment letter I received from the consulate in Abu Dhabi states they accept a joint sponsor for K1 and I also emailed them and they replied that they do.

For proof of my dad's income I am sending 3 years of IRS transcripts, his pension statement verification letter showing what he collects monthly for life, his social security letter proving what he collects for life, a letter from the bank office stating how long he has his checking and savings account with the bank and also his savings amount, one year worth of bank statements showing the monthly retirement deposits, and also proof of his american citizenship (nautrialization certificate)

Has anyone ever had any success using a senior citizen that's retired as the joint sponsor?