All of your children are protected by the forced heirship rules.

If you have two children from a first marriage and two from your current marriage, you have four children and they, together, are entitled to three quarters of your estate. The fact that your ex-spouse has received a very favourable divorce settlement that her children may inherit is irrelevant.

The children of your spouse or partner are not your children. They do not inherit from you, unless you adopt them.