By the time this is published, you will have resolved the question and I expect that you decided to accept it. It is clearly not going to profit anyone to have an "Oh yes I did", "Oh no you didn't", kind of argument, or to engage in a dispute over whether an email message constitutes formal written notice or not.
The fact is that this teacher wished to go, probably having secured another post at the 11th hour. If you were to insist on the rigid interpretation of the contract, she would be obliged to serve for a further term, but it would probably be counter-productive for your pupils to have a teacher who may be resentful and unco-operative, even if you cannot easily find a replacement in the time available.
Although the contractual obligation is quite specific, an employer has the right, in any case, to waive the requirement of notice. In a case like this, it makes practical sense to exercise it, however much it goes against the grain.
If a parent wishes to withdraw a child from the school, must this be done in writing?
Ideally, yes it should, but it is difficult to force people to do the right thing, if they are not inclined to do so. What matters here is the pupil's future and, if the parent announces that the child is being withdrawn, one needs to know where he or she will go in future. If the parent will not provide that information, the school should alert the education welfare service, which is in a position to follow up by a home visit.
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