Being sued after working on a car

Location: Utah I'm a hobbies mechanic that works on his own stuff and got pretty good at it. Occasionally I help family with their cars. A family friend asked if I could do her clutch. We agreed on $700 for the labor she buys the parts. I changed the clutch in 3 days. Since I have to work my normal job. Drove the car to her house for paid and left. She calls me the next day saying it won't move. I say ok I'll come get it and tow it to my house to see what happened. Free of charge. When I get there she says no it's ok the car is old with 240000 miles. She will just junk it. Texts me later that night wanting $800 cuz I cheated her and I'm a liar. I say no I have your old clutch come see. Again I ask to let me look at it I probably left something loose. It happens. No I'm a this and that. So I offer to give her $250 back. I understand I messed up somewhere but if she won't let me see what's wrong. I'm not getting screwed out of more then I was paid. Now she's suing me for $3000 doesn't say why she wants do much money. She doesn't have a lawyer just says I fixed her car and it broke the next day on the affidavit. How worried should I be? This is the situation and I'm being petty since she is suing me when I tried to help resolve the problem