Fair enough. A lot of readers love Harry Potter. Then again, Andrea Barrish is 27 years old.

That probably isn't the demographic author J.K. Rowling had in mind when she penned the series about the exploits of the teenage wizard-in-training, but Barrish, a Web developer by day, isn't alone. She is the leader, or Head Girl, of Potterdelphia, a Harry Potter discussion group that meets every third Sunday of the month near Rittenhouse Square. Ages of the 50 Potterdelphians range from 12 to 60, with Barrish estimating the median age in the mid-20s; many of the members say in their profiles on the group's Web site that they joined in order to find older fans.

Despite some Potterdelphia members' ability to buy alcohol, Barrish says that few people stop and stare when the group convenes. "I think the only time we got funny looks was when we went out to dinner before we saw the [fourth] movie, [and] most of us were in costume. Some people wore uniforms styled after the school uniforms they wear in the movie. One guy dressed as [benevolent groundskeeper] Hagrid and his wife dressed as [headmaster] Dumbledore." That particular post-discussion trip to the Olive Garden was frowned upon by the waitstaff when the group started playing Harry Potter Uno at the table.

But Barrish has no trouble justifying the Potterdelphians' Star Wars-level of fanaticism. "I think [Rowling] writes these books so that everyone can enjoy them and doesn't dumb it down for the audience," she says. "She knows that children are more mature than people will make them out to be and adults can relate to it because you can see it on a deeper level than children would … adults know more about world history, politics and religion so they can read more into it."

And now Potterdelphia is diversifying. An event planning committee has been formed to get beyond the once-a-month discussions. A summer barbecue and an all-ages Yule Ball are currently in the works. "[The Yule Ball will be] kind of like a prom-type event," explains Barrish. "We'll have food and there'll be a DJ and there'll be music and we'll have Harry Potter-themed door prizes and recipes."

Barrish stresses that anyone is welcome to attend a Potterdelphia event, even if they aren't an expert: "Everyone finds different meaning in the books and the stories … Single people, married people, straight and gay and Christian and Jewish and atheist. All these people get together and they have one thing in common."

Meeting other people with that one thing in common is why Barrish says she feels the need to meet up with other Harry Potter lovers in the first place. "My husband doesn't come to the groups," she says. "He says that's my thing."

Potterdelphia

meets the third Sunday of every month at 2 p.m. near the goat statue at the southwest corner of Rittenhouse Square, or, in the event of rain, in the cafe at Barnes & Noble, 1805 Walnut St. Visit www.potterdelphia.com for more info.