If the spouse has a brokerage account and also Credit Union accounts set up before she gets any inheritance funds, will the accounts be considered as marital property as the inheritance funds were put into the previously owned brokerage account? She had no separate accounts before marriage. Does she have to prove separate ownership of the accounts before the inheritance money was posted?
Are you saying that she took inheritance funds and titled it into a jointly held brokerage account? If so, you would be making the argument that by depositing the funds into a jointly held account, she in essence gifted them to the marriage. Of course she would argue the opposite; the outcome will depend on looking at all of the factors in your case. For instance, were the inheritance funds only there for a brief period, did you have full access to remove them at any time, was there an agreement between you and your spouse regarding the inheritance funds, did you also contribute to the fund, etc.