Papermover
What makes a big difference is the amount one-to-one help children get with learning to read, and as u are clearly providing plenty of it, this is making a difference.
The method by which this is done is far less important than phonics fanatics claim.
It would be insane not to start with teaching the main sounds for the 73 main English spellings (as exemplified in the words A, at, bat, cat, cot, cut, dad, hat, mat, pat, sat, rat, set, sit, get, net, fit, kit, jam, leg, van, wet, box, yak, zip,
quit,
the thing, chip, pitch, ship, station,
mate, main, may, tea, tree, here, kite, fly, high, pie,
rope, road, go, toe, cute, cue, new, out, now, boot foot,
autumn, all, crawl, arm, hair, care, her, third, turn, or, more,
cinema, fence, kick, cage, cadge, vision, was, squat, worm).
But even such words children don't read fluently until they recognise them by sight.
This is even more true of words in which some letters have irregular pronunciations (any, both, kind).
Beyond the basic level, it's simply practice that turns children into fluent readers. (My 6-yr-old grandson gave me another perfect demonstration of that today with Horton Hatches and Egg.)