PARIS: I’m not allowed to have mac and cheese.
Paris is allergic to dairy products, which was introduced in the episode, “Concert Interruptus” (Lorelai ordered her a cheese-free pizza). Someone eating something they’re allergic to isn’t a “splurge”, it’s a potential medical emergency!
Paris asks if Stars Hollow, a town of less than 10 000 people, has a 24-hour pharmacy in case she has a severe allergic reaction. Unbelievably, they do! In real life, the nearest 24-hour pharmacy to them would be in Waterbury or Hartford.
Rory may simply be lying, eager to keep Paris there so she is not left alone with Jess. If so, she’s taking a bit of a risk with Paris’ health in the process.