Can a convert to Islam continue to be married to a Non Muslim Husband?

My friend who has converted to Islam from hinduism about 6years ago is 38years old married to a hindu.She has converted to Islam by reading about it on the internet and now beleives in the allmighty Allah and his Rasool (PBH) and is practicing Islam without the knowledge of her husband. Please let me know wether it is haram for her to stay with her present husband and wether marriage is void.she says when she took Islam Allah knew about her marriage and he should only guide her through this and is very confused.

Dear Brother / Sister,

If the man is not a Muslim then the nikah of the women with him becomes invalid. It is necessary for them to separate. If they do not separate (divorce), the woman will be still a Muslim. But she becomes a sinner. And they will also have an adulterous relationship.

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