if you're going to do halter you need to start working her NOW, it'll take at LEAST 3 months to get her into halter form. Lots and lots of trotting, start out with about 10 minutes and work up to 20-25. Neck sweats will be your friend to get a refined neck and throat latch. Excessively groom her and you'll be on your way (: I am learning all this too, with my colt I decided to take this same dive. I bet you'll have better luck though, as my colt is very short in comparison most halter horses in his age group. Good Luck, if you want any help message me (: I have a whole team set up lmao if I don't know the answer I can find someone who does.