No "easy tell" for sex. You are going to have to get it popped or probed. These 2 things if not done properly can hurt your snake so you should only have them done by someone who is experienced.

Age is hard one too. They grow depending on how much they eat. If you BP wasn't fed much its not going to grow nearly as fast as one fed often. But if post the weight and maybe some pics someone more experienced might be able to give you a estimate.