Most prayers for a broken marriage assume you know what you want. Restore it. Save it. Fix it. But some people praying this prayer don’t know yet. They know the marriage is broken. They don’t know what they want God to do about it.
That is a completely honest place to pray from. Romans 8:26 says the Spirit intercedes when we don’t know what to pray. You can bring the whole complicated thing — the love and the damage and the exhaustion and the ambivalence — without having sorted it into a clean request first.