All perfect praise be to Allaah, The Lord of the Worlds. I testify that there is none worthy of worship except Allaah, and that Muhammad is His slave and Messenger. We ask Allaah to exalt his mention as well as that of his family and all his companions.
First of all, we ask Allaah to make a way out to your difficulties and hardships. If the situation is as you mentioned in the question, that your wife neglects the prayer, does not wear Hijab, and backbites your parents and does other sins which you mentioned, then she is disobedient to Allaah and to you as her husband. We have already clarified in Fataawa 85402 and 89480 how to deal with a disobedient wife, so please refer to them.
You should know that you should give each one his right; you should fulfil the rights of your wife, and be kind and dutiful to your parents according to your ability. Your wife did well when she was respectful to your mother when in her presence, but was wrong when she backbit her in her absence. So, you should advice her, and remind her that what she did is a great sin, and frighten her with Allaah's punishment, but you should not obey her in not visiting or not taking care of your parents. So, try to rectify your wife taking into consideration these matters.
If the procedures of dealing and treating a disobedient wife which are mentioned in the above Fataawa are of no avail, then there is no doubt that divorcing her is better than keeping her since she neglects the prayer, does not wear Hijab, and backbites your parents who have a greater right on you than her. The Prophet was asked about a woman who was of a lesser evil than this your wife and he ordered the man to divorce her. Laqeet Ibn Sabirah complained to the Prophet about his wife's bad language, so the Prophet told him: "Divorce her." [Abu Daawood] The jurists are of the view that it is permissible to divorce an ill-conduct woman. Al-Buhooti from the Hanbali school said: 'It is permissible to divorce for a need, for instance because of the wife's bad behaviour.' Moreover, they are of the view that it is desirable to divorce her if she neglects the prayer. Al-Buhooti further said: 'It is desirable to divorce (a wife) if she causes harm,…and also if she abandons the prayer or does not wear Hijab and so forth.'
So, we advise you to try as much as possible to turn your wife into a righteous woman, but if she refuses to obey you after using the Islamicly legislated methods of treating her, then divorce her and Allaah will bless you with a better wife, Allaah willing. Divorcing her before having children is better than divorcing her after having children.
For more benefit, please refer to Fatwa 90385.
Allaah Knows best.