Hi Tracey,
My ds suffered quite a bit like that as well. It's not fun for anyone. I don't know quite when it will stop, but 4 months is probably around the average. With my ds it got better at 18-20 weeks.
Is there anything you can do to soothe her through the crying? Have you tried bicycling her legs? I also used to have some success doing shush-pat, but instead of patting his back i would pat the top of his diaper. Someone told me it helps babies focus the gas a little, and that seemed to be true for us.
If you want to post your EASY routine, we can have a look and see if anything needs tweaking.