What can we do to help someone who skipped from probation in California?

What you can and should do depends upon several variables. Was it a misdemeanor, or a felony? You should hire an Attorney to calendar the matter and appear in Court. Use only an experienced, local attorney who emphasizes Criminal Law in their practice and will appear personally. The Public Defender will generally not step in unless your friend is personally present.

Convince him to return. Hire him an attorney. He has an arrest warrant out for him. For him to handle this, he must turn yourself into the court, with or without an attorney, and try to negotiate a new plea bargain on the outstanding charges and warrant. Doing so voluntarily will result in a better outcome than you being brought in cuffs to court after arrest on the warrant. That will happen if you come in contact with law enforcement or customs anywhere in the US. If this was a felony, he must be personally present at every court hearing and appearance. If this was a misdemeanor, his attorney can appear in court without him being present, and any plea bargain deal could be handled by notarized paperwork. If this is in SoCal courts, and you're serious about getting legal help doing so, feel free to contact me.

Is she still in California? Does does she want to deal with it? I'm not even sure what you are saying. Did she walk away from the program or completed it but was still on probation? If you are near the Bay Area call me. If not I can probably refer you to someone good, but this case definitely needs a lawyer to minimize the pain.

She should contact a California attorney to have the attorney check on the status.

Hire a lawyer to recall the outstanding warrant and have probation reinstated with the least amount of punishment (or none) handed out.

The best advise is to help her get back on the right track. Just because she "skipped" does not mean probation is aware. Hire an attorney to make contact with probation. With any luck they have not sent a recommendation to violate her probation. If they have the attorney could handle the probation hearing.