Is it legal for her to just leave? She did not hurt anyone?
Answer:
Boy.... This is a good one...
Yes it is illegal! You need to contact the owner of the vehicle or leave your contact information. It always better to call the police (even if they do not come out).
Looks like she did not have a valid driver license on that date.
So, the hit and run plus the non driver license carry criminal sentences up to 6 months per count. The fine is about $1,000.
The other issue we see (other than the fact that she is driving while holding her dog) is that in California you must report any accident that has damages of more than $750 or you could be fined. With the type of car she drives, it is likely that the $750 is met.