YTA mostly, but my verdict is a slight ESH, and that's solely because of your edit to add that she apparently (?) used money that was supposed to go to the mortgage (though, if it's hard financially, why did she go on a trip in the first place?).

There is no reason she would need to get your permission before making changes to her own body, nor does she need to report to you first. I do think that these things are of such a nature that she should have made it clear to you beforehand, but ultimately, it's her body and her choice what she wants to do with it and that doesn't change just because you are her spouse and seem to be opposed to her getting tattoos. That might be why she didn't say anything though.