Thank you for your patience, and I am sorry that I was not online when you finally returned. First, a response to a petition for legal separation must be served and filed within 30 days--not 90 days. You may use form FL-120 to respond. The following link will take you to a copy of that form:
California is a no-fault divorce state, so the only question before the court is whether there are legally sufficient grounds to grant the divorce. The options are (1) irreconcilable differences, or (2) incurable insanity. Unless you are requesting legal separation or divorce on the basis of incurable insanity, your wife's mental state is not relevant to the divorce petition itself.
If child custody is an issue, then you can make your wife's mental wellness an issue for purposes of child custody. Hypothetically, if she is unemployed or underemployed as a result of her treatable mental state and if child support
or spousal support
were issues in your case then you could make an issue of receiving treatment for her mental state as part of the argument that it is necessary for her to maximize her financial support for herself or your children together. However, under neither circumstance could she be forced to get treatment (although there could be financial consequences to her if she did not). So it gives me no pleasure to say it, but there is no perfect solution for that; adults are generally allowed to choose to remain mentally ill as long as they are not placing themselves or others in physical danger. Again, it gives me no pleasure to announce this, but please keep in mind that the experts are not credited for unaccepted answers and even where I can not get for you the ideal result, my hope is that you can at least feel confident in your knowledge of your rights so you can get the best legal outcome under the circumstances, whatever that outcome may be.
Going back to the original issue, it is very important that you get the response filed and served within those 30 days. From there, the case next step depends on what course of action she decides to take.
I understand that you may have follow-up questions. Let me know if further clarification is needed. Thank you.