Legal Question in Family Law in California

It depends on when you separated, when you decided not to reunite, and when the contents of the accounts were earned. Earnings during the marriage up until you separate without intent to reunite, are community property. Each is entitled to 1/2 those funds plus 1/2 of any return on the funds if they are invested. It doesn't matter whose account they are in. Neither of you are entitled to any funds earned before marriage or after separating without intention to reunite. So you are not entitled to "half her retirement." Only half what was put in the 401k after the wedding and before deciding to separate and not reunite. Legal separation is irrelevant, so stop worrying about that. It is physical separation with intent not to resume the marriage that cuts off the community property character of earnings and savings.