Adorable! I would describe her as a brown tabby and white Domestic Shorthair. A sideview picture, as StefanZ said, would be helpful for IDing what kind of tabby pattern she has.
So cute! I would describe her as a brown ticked tabby and white domestic shorthair. Since she is ticked on the body and has some mackerel stripes on her legs, my guess would be that she has just one copy of the gene for ticked tabby pattern. Ticked tabby is dominant, so it's likely that one of her parents was either ticked tabby, or solid in color with a ticked ghost pattern.
Ticked tabby is associated with the Abyssinian breed, however Luna doesn't resemble an Aby in other ways, so if her ticked tabby gene came from an Aby ancestor, I expect that it would be far back in her family tree. Most cats are not any particular breed.