Susie,
Sorry for the delay. Today has been one problem after another. Anyway, enough of my moaning...
Vocab is a tricky one. It's not something that one can improve quickly. It's about immersing yourself in language as much as you can. That can involve the obvious such as reading fiction but also listening to decent radio programs, reading the internet, reading poetry, watching tv (good tv - not Eastenders!), reading magazines (probably not Hello!) and lots of other things. The main thing is that your child enjoys the content. Don't force them to read boring books they don't care about. They'll just read but not absorb. I'm a fan of Stephen Fry. He is a master of English without trying to show off for the sake of it. Download some of his podcasts from his website but be careful, he's not always suitable for children so best you listen to them first.
My personal opinion on vocab lists is that they are a waste of time, but as other people seem to want them we have included some on the website. In the little search box on the grey bar above try searching for 'vocabulary'. I think the vocab lists should appear in the results. There is also a vocab booster section in the online testing system (I think it's still there).
Here is another post about vocab written by a person who used to appear regularly on the forum.
www.11plus.co.uk/forum/english/verbsnounspronouns.html#92
Hope this helps a little. Perhaps other parents and tutors could also chip in with ideas.
S