Validity Of Marriage With A Converted Muslims Who's Not A Practicing Muslim
If your friend doesn’t have a problem and her husband doesn’t have a problem then there’s no reason for us to make fatwas about the validity of their marriage. On the day of judgement they will be answerable for their own deeds according to their knowledge and effort. In the meanwhile we’re supposed to stay focused on our own deeds and make sure that we can qualify for God’s paradise.
There’s nothing which invalidates their marriage. Regarding adherence towards religious values and religious obligations in the context of marital relationship, please refer to the following advice of Ghamidi Sahab : Please refer to the video below from 1:28:21 to 1:31:04 https://youtu.be/hzSwD2Nq5gg?t=5301