Tobiano is causing white to cross at her tailhead, and on her neck. It is also the reason she has high white on all four feet. Sabino is probably the other white pattern at play here - the white is very "messy" with really messy edges. Sabino also likes face white to be fairly symmetrical, hence the T on her nose. It's also the cause of the chin and throat spots.
She is a textbook tobiano. White lower legs. White on her bum and half-white tail. As little white on the face as possible. White on the neck interfering with the mane. Pawprints.