Had a meeting with DD's HOY on Friday about her lack of progress and she agreed to keep in touch with me by email.
I'd emailed her once before, out of hours, about her GCSE choices as it had to be answered soon and I leave for work very early. I felt bad when she answered immediately.
She emailed me on Satuday night about some homework DD hadn't done and whilst I passed on the message to DD straight away I feel uncomfortable answering her at the weekend but then not answering her feels rude too. I'm not sure what to do for the best. 
I'm a public sector employee who used to be plagued by emails and texts by a previous manger whilst I was off duty and I don't want to encourage the HOY to be replying to me on a Sunday, she should be enjoying her weekend!