Ok, typical Amber reply coming up.
Don't worry. Some people spell naturally (one of mine has a photographic memory and doesn't need to think about it) and others don't. If your child is producing phonetically plausible spellings of words, as the teacher seems to imply, but writing fluently and creatively, then that is worth more than scoring full marks in spelling tests (which test only how well children do in spelling tests, nothing else). It is a very well known fact that children will not always/often use correct spellings in written work even if they got the same words right when they were tested. Try not to worry about it - she is still very young. Personally I would not go down the route of any specific interventions- these things usually sort themselves out and you don't want to discourage her from writing for fear of getting it wrong. 2 of my own children learned to write using 'emergent writing' techniques because they learned from a Scandinavian teacher. They had no spelling tests at all until they were about 10 and have always been very creative. The spelling kind of sorted itself out as they got older. And now we get a great mix of creativity and spot on spelling.
I would echo the teacher's view (ok, I would, wouldn't I?) that this will not disadvantage your daughter, and indeed would try not to do anything specific abut it as you may kill her urge to write, which would
disadvantage her, possibly forever.