Hi Hercules:
My Maths isn't the same thing but is an on-line tutorial/ homework programme that has powerpoint style lessons explaining a concept (images & writing/ no video) & then homeworks which are marked for you and which the student can 'rate'. Results are fed back to the teacher & there also are a range of maths games for practice.
My advice to you is that if you DD enjoys math and you are struggling to work out what next have a look at Kahn Academy:
This is US based programme but entirely free. US school grades are 1 year behind - so for year 5 - you'd want 6th grade work - but this is maths lessons (videos - narrated 'blackboard' work) and then various exercises which are marked.
Info on Kahn Academy is here: www.khanacademy.org/ - click learn & then math & then 6th grade & see how it goes.
----
other possibilities which you would have to pay to join include:
Komodo maths: komodomath.com/
Maths Whizz: www.whizz.com/
Mathsfactor: www.themathsfactor.com/
Mathletics: www.mathletics.co.uk/
and
IXL Maths (nobody has said much about how good it is yet as they have repeatedly for the others above - but people are starting to ask about it on MN - if someone is using IXL Maths please let us know what you think about it): uk.ixl.com/
The Plymmouth Mathematics Enhancement Programme materials for primary level are here: www.cimt.plymouth.ac.uk/projects/mepres/primary/
If you haven't come across it NRICH maths (free from Cambridge University) has all sorts of maths puzzles to stretch thinking skills in mahts: website here: nrich.maths.org/frontpage - there are problems to think about, hints/ solutions & full answers.
I would also heartily recommend Woodland Junior School MathsZone - which has all sorts of resources for primary maths curriculum: resources.woodlands-junior.kent.sch.uk/maths/index.html
Finally there are a number of free on-line maths worksheet websites - for more work/ practice in maths - just select the area you want to work on.
Worksheet Works is still in Design stage (BETA) - but there are some nice resources here: www.worksheetworks.com/math.html - this is nice because you can design worksheets = #of problems/ level of difficulty/ etc...
Math drills has a huge range of worksheets: www.math-drills.com/
both sites include answer sheets (just remember to print them out when you print off or make your worksheets).
----
Your school sounds as chaotic as ours and my genuine advice is yes, do raise it with the school because they should be appropriately differentiating work for more able pupils, but also go and look for solutions that work for you at home. We found that our school was very unwilling to recommend what to do at home or provide extra work for DD1 when she was struggling and we went the route of Mathsfactor to ensure good calculation skills and a building block approach to maths skills.
Obviously your DDs situation is quite the reverse but it sounds like maths is 'her thing' and just as a parent would go out of their way to support dance, music or sports interests - you should consider exploring what is out there to let your DD continue to be challenged and enjoy her maths.
HTH