How to help a woman who is being abused?

I’m not sure if this is allowed, but I came across a situation today where I saw someone being verbally abused. I went to 7-Eleven and noticed a man yelling at a young woman to get out of his car. When I came out of the store, I saw that she was out of his car and he sped off. She was crying. I went to ask her if she’s okay and if she wants me to wait with her if she needs to call anyone. She said the man has her phone. I told her she can use my phone to call someone. The man came back and looked like he wanted to talk to her from inside the car. I asked her if she would like me to wait and she said yes. I went back to my car and waited with my mom for a little while. Maybe about 10 minutes later, the man gets out of his car and walks inside the store. She comes over to my car and says she’s okay, that we don’t need to wait anymore, that she is probably leaving with him. I asked her if she’s sure and if she’s comfortable leaving with him. She said yes. My question is, should I have done anything more? Maybe offered her a ride? I felt uneasy leaving her there. She was clearly very upset, but I’m not sure what else I could have done without involving the police.