there is a concept in tax law referred to as equitable ownership. if you were an equitable owner you could deduct the mortgage interest based on Phan, TC Summ Op 2015-1 even though you are not liable for those payments.
the decision for the taxpayer rested on the fact that the taxpayer occupied the property, did everything an owner would do paid all the bills, maintained the property including making repairs and improvements,
you live out of state, so a key factor occupying the property is missing. in my opinion, you would not qualify to be an equitable owner so you get no mortgage interest deduction. I offer no opinion as to whether those mortgage payments represent a gift to your DIL which would require you to file a gift tax return if the annual payments were over $15,000
