Sorry but nobody with PKU should be eating any kind of real dairy products – regardless of their daily Phe allotment. NO cheese, NO yogurt, NO milk, NO icecream. That is not advisable. These foods are much too high in phenylalanine. Although butter is an exception ….1 Tablespoon of butter or 15 grams has only 6 mg of phe which is low. Your mom should stick to fruits and veggies (with the exception of corn and peas), PKU formula, special low protein food products you can order online (insurances usually reimburse for these), and maybe some limited cereal and white bread products. Although I did find some imitation cheese slices for my daughter that are very low in phe. I hope your mom sees a dietician to help guide her through this nutritional maze. It can be difficult. I wish you and you mom luck.