I have a number of questions/ comments about this issue:

1) Since you are a biologist (I am also and will finish my dissertation and defend in the next couple of months-yeah)I assume that Hardy Weinberg is not your name but refers to the equilibrium :-)

2) Do federal employees have to pay FICA at all? For some reason I thought that they didn't.

3) Is her income referred to as a 'stipend'. I think that stipends may carry slightly different rules for some issues.

4) Is your wife a) an independent postdoc researcher and received the grant herself or b) working for a P.I. who received the grant and pays her from it? Note: this question probably doesn't matter if the answer to #2 is 'No'.

Since she is a postdoc, I don't think that the money is considered education-related but it might be if it is a training grant.

These are some things that I thought, if clarified, might help some of the pros here give you a better answer.

Carson