If you file "Married, Jointly" - there is only one tax refund - and it can be garnished to cover federal debts (i.e. student loans). My husband defaulted on his early in his marriage - and as I made significantly more money than him, I counted the tax refund as "mine"... as it was the money I had paid in. Imagine my suprise when year 2 of our marriage - my $2750 disappearead and "we" got a note from the IRS explaining that our refund was being seized to cover his defaulted student loans..
We got past that, all our debts our current - life is pretty good. But I will never forget that when you file "married, jointly" - there is no yours, there is only "ours".