You're not really giving enough information. You say you require a larger gap to merge. How big is it? 50 yards? 100?
It sounds from your post like you both could use some driving improvement. If she's had 2 wrecks and 4 tickets, she probably needs to calm down. But if you're so timid that you piss off the driver behind you when you're waiting to turn left, that can cause wrecks too - An angry driver is an unsafe driver. So you probably need to get more comfortable with driving.
You both could probably use some work on handling the car at its limits (like you would have to if you slipped on ice or you had to swerve to avoid something at the last minute) Most drivers are not very good at this because they never get any practice with it - - and if you do practice it on the street you get pulled over
A good way to get great driving experience is to find your local autocross club and start driving in it. They're very safe - the worst you'll hit would be a traffic cone since you're the only car on the course - they're low speed - if you get to 40mph you're in a VERY fast autocross, and it really teaches you how cars behave at their limits.