It's those quantum leaps that seem to have defined her developmentally from day one. So Ruf4. She can't-can't-can't-can't....then *bam* (no practice, no additional instruction, I mean)
DD1, my 2E girl, is very like this, though her leaps aren't quite so extreme. She was middling along on the piano making SLOW progress, then one morning came out and saw the piece DH was playing still on the piano (not hugely advanced but way above her "level"), and decided to have a crack at it. And off she went... She started yr2 unable to read and ended at roughly end of yr1 level, which was good steady progress, but first week of yr3 the librarian told her she had to take novels home now, so being a fairly compliant girl (at school) she did, and after a few minor teething problems her reading level leapt ahead.
It's frustrating to know how laborious sequential learning is for her and how stunning her leaps can be, but to also to understand that the leap has to come by accident it seems. It can't be pushed, or rather we haven't yet figured out how to deliberately push that gestalt in her understanding.