Country Clubs often serve under 21 patrons with their parents permission and supervision, it varies by state.
I looked up PA just to be sure and it is 21 here.
"The minimum drinking age in Pennsylvania is 21 years. Minors are prohibited from purchasing, possessing, or consuming alcohol, even if it is furnished by the minor's immediate family. Persons over the age of 18 are permitted to serve alcohol, so an exception is made in the possession portion of the law in this respect. Many states have exceptions for consuming alcohol made for religious or medicinal purposes, but Pennsylvania does not have exceptions for either."


