Hey there! First off, she is absolutely beautiful! From what iit looks like, she is likely a mix of Calico, Siamese (Face, ears & brown coat), and Tabby (stripes on her brown fur, but tabby is basically another term for mutt). You could always purchase a DNA test kit. There are a ton of different options and I haven't done it myself so I will not plug anything here. Considering Calico males are very rare (and even when it does happen they are more commonly sterile), it wouldn't be surprising at all for your kitty to have multiple different breed types in their ancestry.