Legal Question in Family Law in California

Re: Case law changing custody based on loss of children's ethnic roots/language?

I am not aware of any.

Re: Case law changing custody based on loss of children's ethnic roots/language?

I just took a few minutes to research the case law, and a very preliminary search found many cases discussing the issue of preservation of cultural heritage in the context of laws applying to custody of American Indian children. Those laws are intended to protect tribal cultural heritage. Other cases may be out there as well, and/or it may be possible to show legal support for your argument by analogy. But I did not intend my earlier answer to suggest that you necessarily NEED to find cases that provide support. The MOST important thing to remember is that the legal standard is the best interest of your individual child. Law will only help convince the judge that there is precedent for considering a factor you want him or her to consider. But you must still show it is in your child's best interest to have what you believe is now missing from the child's life.