I don't have the deck so am not sure which correspondences she uses; but if it is the Gra pattern for the Hebrew letters then the first attribution to these in connection with Tarot was made by William Westcott (one of the founders of the Golden Dawn) in a lecture to the Theosophical society, and was later used by members of the Theosophical society (the Curtiss's) in two books in the early 20th century - so might be better described as the English speaking Theosophical school than a continental model - these were later used in late 20th century decks such as the El Gran Esoterico (which led them to be described as 'Spanish school'). They do not match up with Levi, Papus or Wirth, and Etteilla as far as I know never made any Hebrew letter correspondences. If it isn't the Gra then it will probably be different to Levi, Papus, Wirth at least in as much that no doubt the fool is probably attributed to the letter Tau than to Shin.
Her Decan planetary rulerships are also different (as both English and Continental schools used those based upon the Chaldean order) - so both together (Hebrew letter attributions and decan planetary rulerships) result in a unique set of attributions that differ to any traditional school.
I'm not sure what her sources are, but in the book for the deck Christine claims that Etteilla assigns the Fool to the letter Tav and to the Sun, and so these are the correspondences for the Fool in the TotHL. After explaining the variations of other Tarot traditions, she says, "...the only arrangement that remains consistent when carried over onto the Kabbalah Tree into the astro-alchemical medicine formulas and back to the ancient Astrology is the pattern that Etteilla passed along. Therefore, Etteilla's esoteric correspondences guide our choices in Tarot of the Holy Light." But the actual numbering of the cards is the same as with Marseille decks.
As far as the planetary rulerships for decans go, they seem pretty normal. Mind you, I've never been big into Astrology, and consequently I've made very little use of it in Tarot readings. But from checking about on the internet, the rulerships look par for the course, as best I can tell. For example, Capricorn is ruled by Saturn in the first decanate (Ace of Disks), Venus in the second (2 of Disks), and Mercury in the third (3 of disks). But I'm guessing it's how the decans are applied to the cards that's causing so much confusion.
I don't know if this will be helpful to anyone, and I don't want to end up writing a wall of text here, but the basic structure for the decans is like this: Aces, 6's, and 9's, are on the middle pillar of the Kabbalah, and that middle pillar holds the primary decanate for each sign; the 2, 4's, and 7's are on the right pillar, which is considered the second decanate; and 3's, 5, and 8's are on the left pillar, which is the third decanate.
So if you laid the cards out in the order they're meant to be read, astrologically speaking, it looks something like this (using Disks as an example):
3 of Disks | Ace of Disks | 2 of Disks
(Capricorn ruled by Mercury) (Capricorn ruled by Saturn) (Capricorn ruled by Venus)
21-30" 1-10" 11-20"
5 of Discs | 6 of Discs | 4 of Discs
(Taurus ruled by Saturn) (Taurus ruled by Venus) (Taurus ruled by Mercury)
21-30" 1-10" 11-20"
8 of Discs | 9 of Discs | 7 of Discs
(Virgo ruled by Venus) (Virgo ruled by Mercury) (Virgo ruled by Saturn)
21-30" 1-10" 11-20"
EDIT: Umm, that formatting didn't quite work out the way I envisioned. Just imagine each set of three in distinct columns, one lined up beneath the other....
Better yet, here's an image:
http://imgur.com/XtKeD4D (Be sure to click the image to enlarge it.)
Note that all three cards for each sign are in the horizontal rows, and the degrees are the same in the vertical columns.
The decanates will also correlate to a progression through the months and seasons in a predictable order, the end of one month/season in one suit beginning a new one in the next suit, and so on - starting with the Vernal Equinox in Aries and Wands and ending finally with March 20 and the sign of Pisces in Cups. But I've probably already confused people enough, and I'm sure it's only telling some of you what you already knew. My only point is that, whether you agree with her system or not, there is a definite and predictable pattern there and once you start to get the hang of it it will probably be at least a little less confusing.