Seryph
make up some new random spellings is exactly what court clerks did when they had to switch from French to English in the 15th C, at the end of the 100 years war with France.
They substituted, for example, leave, sleeve, believe for Chaucer's regular leve, sleve, beleve and wrecked many other earlier more regular spellings (e.g. erly, erth) similarly.
But what gets me going is when people claim that poor spellers just haven't been taught well enough.
It's much more the case, as LostintheWash surmised, that there's a genetic component to whether people are naturally good at spelling. Those who aren't have a much harder time throughout their education.
Mercifully, with speech recognition getting better and more widespread, this will matter much less in a few decades. Until then, let's be a bit more sympathetic to poor spellers.
In OPs case, i recommend again what i said earlier:
Pick out a few of the words which break regular patterns (ticket, comeing, likeing) and ask her if she can see where she went wrong. - Her dd may well do so when her attention is drawn to them.
If not, remind her what the rule is.
But do it gently and in small doses.