No, I don't think Sherri Papini is safe. The kidnappers who captured Sherri Papini are obviously dangerous and disturbed individuals. They even went so far as to burn a message into her skin. Until the authorities do the work they need to do in order to catch the perpetrators, Papini will not be safe.
As she does live in an area where violent crime is present, there still is always a chance that she will be in danger with an unrelated case. If her captors were part of a gang, that greatly increases the threat that should could be facing. If the police do catch the women, the gang would be trying to seek retribution for Sherri's involvement in their arrest.
The kidnappers of Sherri Papini have not be caught and there may be others involved in the crime. So until the details are sorted out and the police can capture the kidnappers, she is not safe. There should be additional protection for her family also. And the reason for the kidnapping has not been discovered, so there is no safe environment for her.
No, she is not safe at all. Kidnappers are so unpredictable and they could hunt you down if they have to. The California mom, Sherri Papini should therefore be careful. Having revealed the details of her alleged female kidnappers to the police, nothing will stop the kidnappers from attacking her once more.