It's very possible that she got knocked out of alignment. Chiropractic work is amazing! I'm a firm believer in that and equine massage (so much so that I'm a certified equine sports massage therapist now! Lol). My horse was recently having trouble picking up the left lead, and I noticed that he wasn't reaching under himself with his left hind leg at the canter on a line, so I had the chiro. Come out and VIOLA! He's all better!
So yes, chiro. Work is fabulous and it might be a good idea to have one come out and look at your horse.