are not obliged to provide for your ex-wife and she has no right to your inheritance.
after your death, any of your children - either from the first wife (Part No. 21; Page No. 161) or the second one - who is still alive shall inherit from you, whether a grownup or a minor.
any wife you leave behind after your death shall inherit from you.May Allah grant us success. May peace and blessings be upon our Prophet Muhammad, his family, and Companions.