If there are marriage issues, you need to discuss with an attorney.
When filing a joint return, it is possible to split a refund between two accounts. It is not possible to change this after filing, however. This is mainly an anti-fraud measure, since in the past, the IRS was sometimes tricked into sending refund checks to the wrong account.
When a joint refund is directed into an individual account, sometimes the bank will reject it, this depends on the policy of the bank. If the bank accepts the refund, you will need to discuss it with your wife or an attorney, the IRS will not help because the money was deposited where it was told. If the bank rejects the deposit, the IRS will mail a check. The check will be made out jointly if the return was a joint return, but whether a bank would accept a check for cash or deposit with only one signature is a question for the bank.
