@mjfales
Regarding house 2, on the face of it, you and your mother were each responsible for 50% of the capital gains and 50% of the capital gains tax, regardless of how the proceeds were split. Your mother probably qualified for the capital gains exclusion on her half. If you and your mother wanted to split the ownership and the capital gains in a different way, such as 30/70 or 60/40, you probably could have done so, but you should have the situation review to make sure you pay the proper tax.
Regarding house 3, on the face of the transaction, you, your spouse, and your mother each own 1/3 share of the property and you are each responsible for 1/3 of the capital gains. Your stepfather did not own anything, according to you. A money transfer between spouses as part of a divorce is not taxable or deductible to those parties, but that doesn’t change the fact that you and your husband each owned 1/3 of the house, at least on paper.
It would have been much better to consult an attorney or tax professional before the house was sold. It is possible that you and your husband could have quit-claimed the house back to your mother before the sale, so that you would not have been property owners. (Incidentally, when your mother quit-claimed 2/3 of the house to you, she was probably required to file a gift tax return.)
House 3 is where you definitely need professional advice. It is likely that you owe capital gains tax on 2/3 of the house. If that means that the $75,000 is not an equitable share, because of the tax, you would have to discuss this with your mother and stepfather.
I’m not trying to, and can’t, give legal advice. The points I raise are things you should ask your own professional. It’s possible that my views on those topics are incorrect.
