Help Seeing a Low Cost/Free Doctor?

This is a post to hopefully help my girlfriend. First, we live in Washington, South King County Area so lets say basically Seattle. She DOES have health insurance, but it never covers anything!!! We have gone to a doctor twice, but every time we do the insurance company gives us these crazy bills and doesn't cover hardly anything. She had to get shots, at the time she was under 17 and they still didn't cover them, and the bill for shots was $500 +$120 every time we see a doctor, and we've seen a doctor twice. We are both 18, both have jobs since we were 16, and going to college full time, requiring her to be up to date with all her shots.
Now the problem she has is she keeps getting UTI's, even when we don't have sex. We do everything, clean up before and after sex, pee before and after, cranberry juice and pills, azo, and prescription antibiotics, so basically we want to see a doctor again to look at it more thoroughly.
Her parents struggle with money, her mom being self employed, and her dad is disabled and fell into a scam so they struggle with keeping the house. So everything we do comes out of our pocket, when she goes to the doctor and we get these bills, they pass them off to her. Again, were both 18, have jobs, full time college students, and have health insurance, but I don't know what to do. We can't keep being charged $120 to talk to a doctor for 5 minutes just so they can write a prescription that doesn't really help. Is there a way for her to see a doctor for free or very low cost, this is ridiculous.
We already go to planned parenthood and get free birth control, but a doctor cost is not free there, and we get charged $120 to even see one, and they suggested a pelvis exam but we just can't afford another $400 on-top of the bills we already have. Help is highly and greatly appreciated :)