if you have the cash, go try some rage bheads. They have a practice head in there. It might be worth the money just to see if it is the bhead you are using. I got bad groups with certain heads also. Slick tricks and rage were the main ones I found that flew exactly with the fieldtips.

but like said, make sure the vanes arent hitting the rest. If you want to stick with those and the beahds are grouping the same spot every shot, then move the rest slightly to the left. Also, just check basic things like the peep sight if she has one. Make sure she's not dropping her arm on the shot. Make sure nothings lose. Sometimes a small issue can cause bigtime probs. Try the fieldtips and see if they go back to grouping the same. I had hell with my rest and my issue was dropping my arm on the shot.

goodluck and take your time...