Marriage

1. Her marriage can be voidable and may be annulled by a decree of nullity  by leading evidences of husband's earlier marriage and fraud committed by her husband and fathering a child (a DNA test can be Ordered by a Court). 

2. But she cannot seek interim maintenance and or alimony from him.

She can seek maintenance for her daughter by establishing the daughter was born to both of them and the he is the biological father of the child.  She can file a domestic violence case against him by which she can claim maintenance from him establishing the fact that they lived together , begotten the child and he abandoned her.  Consult a local lawyer and take his advise before proceeding.

No proof of marriage means no marriage. There is no need for divorce because there was no marriage to begin with. And only if proof exists then you can seek to make the marriage null and void because he was married earlier. On maintenance, Advocate Kalaiselvan has given you perfect advice.  She was in domestic relationship with this man and she would therefore be entitled to maintenance under the Prevention of... Domestic Violence... Act of 2005. No marriage is required to get maintenance under this Act. Therefore, Advocate TajobsIndia's advice "But she cannot seek interim maintenance and or alimony from him." is outrageously wrong but I am not surprised because TajobsIndia's advice is usually wrong. He should stop giving advice.