ANSWER:

If this was the first or second divorce, She cannot get married to the other man as her first husband has taken her back and she is already married to him. Revoking the divorce is the right of the husband and the wife has no say in it! If she gets married then it will be committing zina and adultery which is punishable in Islam by stoning till death. If she doesn’t want to stay married to him, she must file for khulu and give him his dowry back. 

Husband recently divorced her by written talaaq, and then took her back before the iddah period ended, by saying ‘I take you back’. Someone had advised her that she is still married to him, but refuses to accept this and is going to get married to another man at the end of her iddah period. What is the ruling on this, will her other marriage be valid?