Legal Question in Family Law in California

You can always file. What will happen after that is impossible to guess with no facts about why she attempted suicide. Who knows if it is about something at mom's house or dad's or neither.

But maybe, just maybe, it's because she has parents who would seize on her suffering and mental health issues as an opportunity to try to fight each other over custody of her. Did you ever think that maybe, just maybe, instead of immediately seeing this tragedy as an opportunity to take your ex wife to court, you should focus on your little girl's obvious pain, depression and mental suffering and try to do something about it WITH her mother instead of against her mother. If the two of you can't see that parenting her together, putting her first and healing her is what she needs, not a new custody fight between you two, then I think we have a pretty good idea why she did what she did.