She is thinking of showing up just to see if it can get dismissed as this might lessen the cost $561. Could that happen if the officer does not show up? Her worry is that the judge might say hey you should have gotten a MIP since she is 20 and that would be a misdemeanor, can a judge up or change the charge…the MIP would be way more we believe and would be reportable since she is over 18.
SLO County is perhaps unusual in that infractions are direct-filed by the police with the courts. Furthermore, the DA does not staff the court that handles infraction cases. So I think it is extremely unlikely that the case can or will become a misdemeanor because the mechanism is just not there to change the filing decision. Be that as it may, if your daughter is convicted, she will lose her ability to drive for a year. So you might seriously consider hiring an attorney to assist her.