Giving legal advice in a situation where you’re conflicted out is a violation of professional conduct rules. Sure, she’s not technically his client for purposes of these notices (though he claimed to be in the arraignment). But at this point his overall fitness/character as a human and as a lawyer, which will come into play if he is ever suspended or worse and seeks reinstatement, is not looking great, and as a lawyer who is also a co-defendant and spouse, he should be a million miles away from giving or looking like he’s giving her legal advice. Most lawyers stay far away from real or perceived conflicts, formal and informal, because it’s a big fucking deal. “I can’t talk to you about this” is absolutely a thing.