Q.holly bushes
I recently bought two holly bushes named Royal Duet Holly ‘Blue Prince and Blue Princess.’ They both have berries on them. Does this mean they are both female? And if so, why have both prince and princess on the label? If they are both female and I have to plant a male, can it be a China Boy or other variety? This is my first try at planting holly and want to have some berries in the winter for the birds. I live in area 5 in Illinois. Thank you.

You are right in thining they may both be females, as females are the ones that produce berries. It's possible that one of the plants was mislabled. This article may be helpful: https://www.gardeningknowhow.com/ornamental/shrubs/holly/how-to-tell-the-difference-between-a-male-and-female-holly-bush.htm