Kirsten, I suppose you know that she should have food with very low amounts of Calcium, Ash and Phosfor. Not sure whether it depends on what kind of crystals she has, but ask your vet about it. Also Sasvermont some very informative articles about this a few years ago - go and search for them.

Hope Luna will get better soon, and she'll take her medicine.

Kisses and headbumpies from us.