Paganism isn't a set religion. It varies from person to person, has no single set of beliefs and can be practiced in any way the follower wants.
There is no need for a pagan to attend any pagan event if they so choose or hold fast to any of the pagan holidays.
I am pagan and never attend pagan events, there is no dogma that says I must. . As a religion, it's a very personal (and private) practice that does not require a follower to prove their beliefs.
If this friend identifies as a pagan, then they probably are.