Hello,
It is very difficult to answer this question.
First of all, I haven’t heard both sides of the situation.
However, the core of the matter: the Torah’s economic system was built entirely differently. In general, matters of property were conducted by the male head of the household alone, and in practice women were almost never inheritors. They would practically join the families of their husband, for better or for worse.
Now the system is entirely different, and there is great contraversy surrounding which of the biblical halachot around inheritance we continue to practice even in an entirely different system, and what we do in light of edicts that the courts enacted due to the large changes, as were enacted in many other categories.
Assuming that daughters inherit – and she can prove (with evidence that is substantial according to biblical law) that she is truly the daughter of your ex-husband, it seems that she has a right to the inheritance. There are many discussions in the Gemara regarding a son that suddenly appears much time after the splitting of the inheritance, and what arises from there is that it seems he is deserving of the inheritance.
As stated, these are general statements, and practically do not have much impact, for the justice between the two of you will not occur in the rabbinic courts, and according to the law in the place where you live it seems that she would join the inheritance.
I hope that the gates of recovery and rehabilitation open up before you.
All the best and much joy,
Rabbi Yuval Cherlow, Head of the Tzohar Ethics Center