I am unsure as to what the purpose would be to re-serve. If you served the party with the summons to appear/regarding the divorce and that friend who personally served the party can attest to personal service, then it would have been solely up to the Respondent to send in paperwork in the form of a response or other motion. If that person failed to do so, then you might be able to simply show that party defaulted (use a notarized affidavit of service by your friend attesting to her personally serving your spouse). If you obtain a default in California, there is usually no need to go further and depending on your motion, the court will either order all party split like it is all community property or move to what you had requested in writing if there were special considerations.