If my 66 year old mother was at a bar and one of the patrons was drunk and fell on top of her breaking her wrist, can she sue the bar?

Your mother can sue the bar based on premises liability, but prior to suing the bar, it may be possible to settle the case with the bar's insurance carrier.

When your mother completes her medical treatment and is released by the doctor or is declared by the doctor to be permanent and stationary, which means having reached a point in her medical treatment where no further improvement is anticipated, she should obtain her medical bills, medical reports, and if applicable, documentation of any wage loss.  Her personal injury claim filed with the bar's insurance carrier should include these items.  Compensation for the medical bills is straight reimbursement.  The medical reports will document the nature and extent of her injury, and will be used to determine compensation for pain and suffering, which is an amount in addition to the medical bills.  Compensation for wage loss is straight reimbursement.  If your mother is dissatisfied with settlement offers from the bar's insurance carrier, she should reject the settlement offers and file a lawsuit against the bar based on premises liability.

If the case is settled with the bar's insurance carrier, NO lawsuit is filed.  If the case is NOT settled with the bar's insurance carrier, your mother needs to file her lawsuit against the bar prior to the expiration of the applicable statute of limitations or she will lose her rights forever in the matter.  CA has a two year statute of limitations in personal injury cases, which means the lawsuit must be filed before the second anniversary of the date of her injury.