It would not of been her teeth bleeding, just her gums. Nylabones are a good alternative to real bones, in terms of satisfying her chewing needs and assist in cleaning her teeth, they are usually made very tough. Make sure you have the appropriate size Nylabone, considering she is a serious chewer, you might want to get a larger, tougher one than is recommended for her size.
Not experienced with deer antlers, but if it is going soft from chewing, then she is doing a good job at chewing as opposed to biting off junks.
If she has bitten off chunks of the Nylabone, throw it away and either stick with the deer antler or as said above get a larger, tougher Nylabone.
Dogs need to chew, it satisfies them so much.