Yes, you can be sued if there was no police report: a police report is not a requirement or prerequisite for being sued. If you were not at fault, she should not be able to get money from you: a driver is only liable (responsible to pay) in an accident to the extent he or she is at fault in causing the accident. If she can convince a court that you were at fault, she can recover from you all costs or damages you caused her, less the $100 you already paid her.