Legal Question in Real Estate Law in California

Possibly, but because you didn't provide any information that might lead a lawyer to think so, I'd suppose the possibility is rather slight. The missing information:

1. Did the deceased leave a will? What did it say? Has it been admitted for probate?

2. What were the terms of the trust that held the ownership of the stocks and real estate?

The basic concept here is that California is a community-property state, but when someone marries, property they owned before marriage generally remains separate, and is subject to distribution by them in their will. If they die intestate (without a will) property they own is distributed according to law, some to the spouse. If there is a will, they can leave their separate property to the Eskimo Relief Fund, or whatever.

In addition, separate property can lose its character as such by several processes. One of these is commingling separate property with community property, e.g. by keeping both kinds of cash in the same bank account. Another way is by using community funds to make mortgage payments on separate real property. This is a very gradual process and would have only slight ownership-transferring consequences in a brief marriage; none at all if the property were fully paid up, of if the payments came out of rent from the property.

In sum, I think you need to take your question, along with a lot more information, to a lawyer who specializes in estates and probate (assuming you are the new spouse).