Originally Posted by smrobs
Just give her time to get settled in and have your vet on speed dial. Start with rubbing her all over to show that you are not a threat and go from there.
It takes time, usually months, for even an experienced horse to get settled with a new owner, farm, routine, and/or herd. To lessen her anxiety, the more time you spend with your new horse, especially touching, and showing her around your place the better. Don't expect her mind to be very focused on 'work' for awhile, but doing simple things can help to get their mind off the new environment worries. We always start by walking them in hand around the perimeter so they know the fence and exploring anything that may get their curiosity up (and to show them that there are no monsters at their new place).
Health-wise, try and make sure that any diet changes are done slowly.
And...have fun together.