Validity of Annulment of Marriage

Hi, Forum mates, I would like to ask for your legal advice/opinion on my sister's case: She got married last year to a man who had a previous marriage but was legally annulled and had 2 children out of that marriage. My sister gave birth last month and that's when her dilemna started. The first wife demanded her husband go back to her and her 2 children because the annulment was invalid because she was not the one who signed the documents but just a relative of the husband whom she verbally authorized to sign the annulment document on her behalf as she was abroad at the time the annulment was being processed (she was into another relationship at that time reason why she agreed to the annulment). She is threatening to sue her "estranged" husband and put him in jail and file for a revocation of license of my sister who is a registered nurse on the grounds of immorality.

My questions are:
1. Is the marriage of my sister valid considering that the court had already a decision to void the first marriage of her husband?
2. Can her license be revoked (she was abroad at the time the annulment was being processed)?
3. Does she has a legal rights to fight for her husband who is now living again with his first family due to fear of being put in prison and the threat to my sister?

Please enlighten us. She really needs help considering that she just gave birth and seems to be suffering now from Post-partum depression.

Appreciate immediate response from anyone.

Thank you and best regards

Jessie

I doubt if she can question the validity of the annulment which she herself instituted.
We have a principle in law called estoppel, a legal doctrine that precludes a person from denying or asserting anything to the contrary of that which been established as the truth by his own deed, acts, or representations.
Applying this principle, if she allowed her relatives to sign for all the needed doucument for the annulment proceeding she cannot now question its validity.

Also..only a competent court can pronounce a certain judgment as null and void. So, the former spouse needs to file another petition to annul the judgement annuling the marriage. Until then, the annulment is valid and binding.

Lastly, I also doubt if an action to have your sister's license revoked will prosper. Her marriage is valid...assuming arguendo that the said annulment is void this does not mean that her marriage with his husband is immoral since she relied only on the fact that his husband is legally qualified to get married with her.