Having 3 kids of my own (9, 6 and 3 years old), I always say, follow your instinct.
But is she unhappy? I think that should be the key indicator, as soon as they don't want to go, cry, sudden change in mood, then the alarm bells are ringing.
I understand the issue with high staff turnover, because every term when they do the assessments just to gauge their progress/regress, I can imagine it is not the best thing from a learning perspective to have intermittent teachers and an interrupted assessment. Not to mention that 8 teachers in 3 years raises eyebrows in terms of management of the creche (and what will the impact be when she is 4, 5 and 6 - these foundation years are quite important).