Should children's photographic negatives be charged for film addition?

The current photography price is the market-adjusted price, and the photo studio should clearly mark the price, no matter whether the price is high or low, as long as both parties are willing. Whether children's photographic films should be charged for guests' films depends on whether the clearly marked photos contain film fees, whether there is a standard for separate charges, or whether there is an agreement between the two parties in advance.

I hope to adopt.