@Midfielder wading into your personal life here.
My advice would be to talk to her about the future of your relationship together, and give an ultimatum. All or nothing, because if she is still invested in her marriage the only person who gets hurt by carrying on is you, down the road. Be honest, be appreciative of the time you’ve spent together so far and definitely don’t accuse her of using you if it’s not a long term thing for her.
Remember she might also have reservations about your commitment. She might not know herself what this is. If she knows you’re in it for real, it might make it easier for her to realise how she really feels.
Good luck