She found out that the man with whom she did the marriage contract does not pray regularly and he mixes with women
If the marriage contract has been completed, with the proposal and acceptance and with the presence of the wali (guardian) and two witnesses, then the woman becomes the wife of the man, then she has obligations like any other wife. He has the duties of providing maintenance and accommodation, and has the right to physical intimacy etc. If the man does not pray the five daily prayers, then he is a kaafir and the marriage to him is invalid, even if he prays Jumu’ah. His visiting bad websites and keeping mixed company are sins which he must give up, but that does not mean that the marriage is invalid so long as this does not cause any harm to the wife and children by exposing them to these things. Warding off evil takes precedence over gaining benefits. Whatever the case, the main concern has to do with the matter of his prayers. You have to make sure that the husband is praying regularly, because the one who does not pray is a kaafir and it is not permissible for a Muslim woman to stay married to him.