If she's charged, she's going to need a criminal defense lawyer to explain all these facts to the court. She must not speak to, or attempt to make explanations to, the police or the court by herself.

You should re-post this under Criminal Law".

She is likely charged with a felony hit and run, with 'prior' felony enhancement. Yes, she has a problem that could put her in jail. Her attorney's job is to try to prevent that outcome.

She’ll learn the actual charge[s] and enhancements filed and get copies of all the police reports when appearing for arraignment at the first court hearing. The charges determine how much ‘time’ and fines could potentially be imposed if convicted.

When arrested or charged with any crime, “what can you do”? No amount of free 'tips and hints' from here or anywhere else are going to effectively help you in your defense, other than the advice [if not already too late] to exercise the 5th Amendment RIGHT to SHUT UP and do NOT talk to police or ANYONE about the details of the case except through an attorney. Most police and prosecutors will happily tell you that 95% of people convict themselves by trying to be 'helpful and cooperative', either during initial contact, questioning, interview or interrogation. She has already behaved unwisely, don't compound it.

Of course she can fight the charges. Raise all appropriate defenses with whatever witnesses, evidence and sympathies are available for legal arguments, for evidence suppression or other motions, or for trial. If you don't know how to represent yourself effectively against an experienced prosecutor intending to convict, then hire an attorney that does, who will try to get a dismissal, diversion program, reduction, or other decent outcome through plea bargain, or take it to trial if appropriate.

If serious about hiring counsel to help in this, and if this is in SoCal courts, feel free to contact me. I’ll be happy to help, using whatever defenses there may be.