Worried about my friend's future. What should I do?

Salaam, I really need some advice about a situation with a close friend. She recently got married to a man who wasn't Muslim. He decided to convert so they could get married, but from what I've seen, it seems like he only did it for her and isn't really living by the faith. It's been weighing heavy on my heart. I'm genuinely scared this might cause problems for her in the akhirah (hereafter). Is my fear justified? How can I best support her in this?