They mean the same thing. But there is a subtle difference in there, that can only be seen if particular contexts are added to the text.
In 1, you just found out that information. Perhaps your father told you himself, or may be it was your uncle who told you, or you found a paternity test result (without looking for it).
In 2, (it should be "figured") you found the information by doing something. May be it was you who did the research in searching for the truth. May be you tracked down the nurse/documents and got to know from the particular source. In essence, you made an effort to know the truth.