Wow thanks for all the replies 
Becca it is a Law MA, it combines a conversion to law as it wasn't my undergrad subject but it is a fairly new course, hence there not being much info available on it. The 8 hours cover all seminars and lectures and this is fixed but it does state on the uni's website that a full time MA should be treated as a full time job, i.e expect to devote 9-5 Monday to Friday to the work needed.
I do intend to use the new governments postgrad loan starting in the autumn that NapoleonsNose mentions, so I'm fine with the funding side of things, just worried about actual income.
Ready agency work is a good idea, that would allow a deal of flexibility. I do my volunteer tutoring all year around so hadn't thought that paid tutoring would be different but I can see how there would be much less demand during holidays so I'll need to look into that, it is a good point!
Imperial that is very impressive, I'm not sure I have your stamina but that is certainly inspirational to see you managed full time work and two teenagers
I know I'm going to love the course and I cannot wait to start it so hopefully that will give me the focus to make it all work, somehow.
Thanks, Napoleon. I do admire you're ambition continuing to work 30 hours alongside a history MA. I did history in my first year of undergrad and I found it extremely difficult! An understanding and supportive employer is so important, my previous employer sat down with me and my uni timetable and we planned out all of my annual leave/overtime/toil to use most effectively. Part time MA's are often tailored to ppl working full time so I hope it all works out brilliantly for you!
Wow fuckweasel that is a lot of hours to fit in a week! Hopefully it all felt worth it in the end? I don't have much of a social life so I don't mind not having weekends/evenings and working 3 days, at uni 2. I just hope it will all work!