What is the ruling of the Sharia regarding a husband and children who psychologically, physically, and financially abuse their wife and mother, refuse to work, and take her money? Is she entitled to separate from them?

If the husband is unjust and abusive, she should try to reach an understanding with him, explain his duties, warn him about the consequences of injustice, and urge him to associate with the righteous. If he does not respond, she should involve some righteous people as mediators. If he repents and treats her kindly, she should thank Allah. Otherwise, she should weigh the options of staying or leaving and choose the lesser of the two harms. She should remind her children of the importance of honoring their parents and the consequences of disobedience, and she should be patient and supplicate persistently, without haste. Supplication is entirely good, for it may be answered immediately, or stored for the hereafter, or avert some evil, and Allah knows best.