a 1:32 twist means it is an older model Staghorn. Congratulations... my friend has the same rifle as you. In fact I attempted to purchase a 1:32 twist but was not able to get one and settled for a 1:28 twist. If the rifle were mine, I would try some of the following loads...

With the 1:32 twist it should be an exceptional conical shooter. I think I would try some of the CVA Buckslayer 300 grain bullets with about 80 grains of Pyrodex RS. If your daughter is going to shoot it, tone them down just a little and see how they do with 70 grains. Recoil should not be too bad. Some of the 320 grain REAL bullets might work good out of your rifle. They shoot good out of the 1:28 twist with 90 grains of Pyrodex RS and homemade lube.

You might also want to try some maxiball. They normally come in 370 grain and with 70-100 grains of powder should take any large animal you might encounter. I just purchased some cast maxi for a reasonable price to shoot out of my 1:48 twist rifles and I am going to try them in my inlines also. In fact I was shooting them with 70 grains of Goex FFFg out of my flintlock with some impressive results the other day.

As for sabots, all I can suggest is to try some different size sabots and see how they act. With that twist, they should stabalize a heavy sabot well. Perhaps something in the 300 grain range with a moderate powder charge...

My friend hunts with the REAL conicals in his. He shoots 80 grains of powder. As for his distances, he is not forced to shoot over 75 yards. He mounted a RED DOT on his and although he is not a target shoot has been able to take a deer every year with it so far. Also they REALs must be easy to load because he suffered a stroke years ago, and does not have full use of his one arm but still manages to hunt with the rifle and load it.... He shoots of a set off shooting sticks....