I agree. Lead her out a few times so she has you there for a bit, even if you ride sometimes and lead others. Maby even take a treat or 2 to help reward her.
Also the getting an experienced horse to come with you would be good aswell.
She will be nurvous in such an environment because horses generally in the wild would live out in the open were they can see all around them, in a bush/ foresty surrounding she proberly feels she cant see all the big monsters hiding in wait to eat her so has to be extra alert :roll: My Banjo used to do the same, altho when he got a fright he would try and take off and buck
Just take it slow and dont turn back if shes getting all scared, just stop and calm her down then continue for a bit.
It will just take getting used to the surroundings for her and paitients from you.