This sounds like a complicated case that should be reviewed by a family law attorney. In California, all property acquired during marriage is community property and is subject to a 50-50 split at divorce. There are a lot of exceptions to this general rule, however, which an attorney can help sort through.
For your second question: If your step mother were to receive one of the homes as part of the splitting of property upon divorce, it becomes her property to do with as she pleases. The only way to have it come back after her death is to be mentioned in her will as a beneficiary. There is no way that you or your father would be able to maintain an ownership claim to property distributed to her in the divorce.
This answer does not create an attorney/client relationship, and is only meant as a suggestion of how to proceed. Due to the facts unknown to the answerer, some or all of this advice may not be accurate. In order to receive a full answer to your questions, please consult privately with an attorney.
This is a question that is difficult to answer without knowing specifics. It can only be answered in generalities. Basically, absent a prenuptial agreement, community property begins to acquire upon date of marriage. At that time, each spouse owns 1/2 of income, appreciation, etc. earned during marriage. Whatever assets (and debts) acquired with community income/assets is also community property. Whatever was acquired/earned prior to marriage is the separate property of the acquiring spouse unless specifically changed into community property.
There is also a spousal support issue here - support can generally last 1/2 the length of the marriage.
If step mom takes a home it would come back to you children upon her death only if she chose to make you heirs to the home in a will or trust. She might not. Without an instrument specifying who gets the property, it would go to her biological heirs. If step mom has no children, Dad could consider offering step mom a life estate in the home, and maybe a bit more cash to live on, and then your dad can determine to whom the property reverts after death.
Please advise your dad to seek legal counsel to determine all of his options.
Yes, I am agriad that this is much to complicatdd to get a quick answer in this forum. Consult with local experienced family law attorney Good luck.
Please note that this answer does not constitute legal advice, and should not be relied on, as each situation is fact specific, and it is not possible to evaluate a legal problem without a comprehensive consultation and review of all the facts and court pleadings filed in the case. This answer does not create an attorney-client relationship.
Sign up to receive a 10-part series of useful information and legal advice about the divorce process.