Can you sue with no car insurance?

[Janet S]

My daughter and two kids were in terrible car accident (tractor trailer) hit her from behind going 50 mph, knocked her clear across to the south bound lane. Whole rear end of car was in back seat. My grandaughter, if she had had a seatbelt on would have been much worse or killed. She was sitting in the middle. My grandson, front seat was bruised up and now is having anxiety attacks. They were all so lucky to be alive. I wish I could post a pic of car but this does not allow it. My question, now, is can she sue without car ins. It was trucks fault. She was sitting at traffic light and he just plowed into her. thanks