It would depend on what happened after dd, I would think. If there was a lot of drama, nasty emails... or if she had been hurt. It could trigger her and cause drama for everyone.
There may be a reason you're struggling. Did you two go to counseling? Was there evidence of remorse? Did he show sacrificial efforts to provide you with safety? Did he allow you to ask questions? Was he defensive? Has he lied about other things? Did he confess, or did you find out? Something seems unresolved. Have you told him you're struggling? I would think that you and him should discuss it first, and if you're gut is giving you red flags, maybe try counseling or an affair intensive retreat that teaches truth-telling in a safe environment. Because she's married now may have the opposite effect. She may want to down play it all for the sake of your marriage or her own reputation. She may not have told her headband she had an affair with a married man. If you haven't discussed your concerns with your husband... why not? Because if you haven't, then I don't think your safety has been reestablished, and I believe it should be addressed.
DD 10/16/16 WS multiple relapses Physical affair, emotional affairs, online affairs In-house separation 06/11/18 Complete separation 01/04/20 Last relapse 01/07/20 Don't be afraid. Don't be dismayed. The battle belongs to the Lord. 2 Ch. 20:15