I'll offer a suggestion. I am not a lawyer.
I think you are barking up the wrong tree when you talk about road signage. The fact is that you were in the middle lane, and the other driver stated to the police officer that you were in the right lane, thus, she believed you would turn right as was required for that lane. Based on that, you got a citation for going straight in a right turn only lane.
My suggestion is that you would know, better than she would, which lane you were in. Obviously you were not turning right, as if you were turning right you would have continued on parallel paths and not collided. You collided because you were going straight and she turned right, into your car.
My suggestion is to go to court and state that you were, in fact, in the middle lane. Your intention was to go straight, thus, you were in a legal lane for straight traffic.
My next question, in court, would involve at what point did the other driver see you at all? Did she see you in the right lane, say to herself "He must turn right there, thus, I can, too.", or did she only imagine seeing you in the right lane?
If she actually saw you in the right lane, did she also see you do the things typical of a right turn? Did she see your blinker? Did she see you slow down? Did she see you look over to the right to make sure the coast was clear over there? Or did she see no blinker, no slowing down and you looking straight ahead? Since your intention was to drive straight ahead, then she would have observed the latter had she observed you at all. Then, having observed the actions of a driver who plans to go straight ahead, why did she "trust" in the right-turn only lane and expect you to turn, thus, avoiding a collision?
There is a similar intersection near my house. I have to make a left turn across oncoming traffic. The oncoming traffic has a right turn only lane. I often see people driving in the right turn only lane, slowing down, with blinkers on. Do I trust them and start a left turn? No, I do not. Not until I actually see the car initiate a turn do I trust them. I know that people sometimes drive with blinkers on for miles, unknowingly. I know that people might slow down to look at a road sign, then drive on straight if it's not the road they want. I can easily imagine a scenario where someone looking for a road, unaware of their blinkers on, goes staight through the intersection when I am depending on them to turn right as I turn left.
Thus, I wait until I see an actual right turn happening (tires turning, etc) before I start the left turn. I don't mind waiting a few more seconds.
My suggestion to you is to go to court and show that the accident could have been avoided if the other driver would have been more aware of your actions. Her side of the story doesn't add up. How could you be in the right lane? You were not driving slowly, as a person would do if they were turning. Your blinker was not on. She should have realized something was wrong and taken appropriate action.