Legal Question in Family Law in Washington

Technically yes, but if you refuse to provide the requested discovery, she can make a motion for leave of the Court to allow her to make this one late discovery request. If the Court feels it is pertinent to her case, and since we like cases judged on their merits, she is likely to prevail. It all depends on the exact circumstances of your case, and of course, which judge you have, but overall, more often than not, she will prevail.

If you have nothing to hide, my advise would be, give her what she asks for, rather than risk having the Court think you're not a nice player, in which case things can be held against you later on down the road at a trial, if there is one.