Her grandmother and her grandfather are both horned so there is a good chance the horned gene came through. Do you have any pictures of your heifer's "horns"? You should be able to tell by looking at this point whether she is officially horned or scurred. Bulls are a lot more likely to have scurs than females in my experiences. Why I don't know.... Her grandsire Monument L1 9841 was an awfully good bull and I owned a son of him. Excellent carcass traits, so I wouldn't give up on your heifer because she's horned. The association is one association and some shows do show horned and polled cattle together. Good luck with your heifer!