"Under U.S. federal common law, the spousal testimonial privilege is held by the witness-spouse, not the party-spouse, and therefore does not prevent a spouse who wishes to testify from doing so. The rationale of this rule is that if a witness-spouse desires to testify against the party-spouse, there is no marital harmony left to protect through the obstruction of such testimony."
Yep, she can testify against him. That should be enough to put some pressure on. She might be precluded from testifying to any marital communications. Different rule.