Hya, I teach science and pscyhology A level. I'll be going back to work in Sept for the 3rd year - hopefully for four days a week. I decided to go back for 4 days - because I know how tired I got before I had DD. I found the first year the hardest and things got better in the second year, mainly cos I had taught things at least once and knew what worked or didn't work.
I also found that working for a department that is well organised, ie well written schemes of work, worksheets, good resources makes life a lot easier. (I once worked somewhere that had nothing - what a nightmare) also Sunday planning is a must - so that you have an idea of what is happening during the week, so if you have a bad night, you can wing it. Good tech - vital
Get the kids to mark each other's homework and tests, and try to get a sixth form tutor group, ok you'll have UCAS refs as well as form reports, but less grief than the younger years.
Keep a copy of all your resources at home, with text books (just in case) handy if you need to ring in a lesson if absent.
I don't know how its going to work out, but I hope to be home by 4pm most days (unless there's a meeting) and plan to spend just one full day working during the 13 weeks hols. and to keep home work to a minimum.
I love teaching, but the main reason I went into teaching, was to fit it around family life. Its not perfect, but when I was in finance - lots of hours at work and home, lots of stress and just 5 weeks holidays!!!!!!!!!
Good luck. If you want any resources just shout, but i'm just a biology teacher at GSCE, but teach general science at KS3 -