Do some longline training with her to get an instant recall.
I have posted this reply many times.
Order a longline (schutzhund type, or a horse lunge line)
Get a prong collar
Bring some very small treats (catfood size)
Attatch line to collar to dog, bring dog to field, let her get used to it for a few minutes, then call her and pop the line.
You MUST pop the line directly AFTER you call her. Let her come to you. If she dosn't come the first time, repeat.
Do this a few times. After a while, she will get the hang of it and realise you want her to come as soon as her name is c