I would have thought MyMaths would be a good resource for KS3. You can set it to whatever level you wish and can choose your topic. There are lessons and homework exercises on every single KS3 topic.
Have you looked at 10ticks.co.uk? They have a variety of worksheets with loads of practice questions on for level 4 to level 9/10. We use them in school as an extra resource but I think parents can buy into the system too.
In the past I've used Succeed in Maths 11-14 for daily maths work with my daughter, as I explained in a previous thread.
Now I've enrolled her on Conquer Maths which we're finding to work really well. The "online tutor" explains the work and she can play back the explanation while working through the exercises. No marking for either of us, and I can monitor her progress in the Parent's Dashboard.
Roberta1 , maybe a bit late for the reply I found the Hilary Koll & Steve Mills books the best eg year 7, 8 or 9 in the subjects calculations, algebra, numbers .., shapes... algebra was very very good the original publisher was a&c black I bought them second hand when I could from ebay, abebooks, waterstones market place, the prices varied quite a bit and whsmsiths for new ones I notice WHSmiths started doing their own version of the above by the same author htmh