I think you should expect more than three pieces of work and would be being perfectly reasonable to push for more, however I have to say that requesting 'regular' meetings (plural) with teachers (plural) is probably asking too much. Her teachers are planning and marking work for hundreds of pupils and meeting with you and your daughter regularly would take up a lot of their time.
How about asking for a meeting with her head of year as a first step? You could raise concerns about the lack of work and ask for the best ways to set up regular contact with teachers. It might then be that one teacher or member of support staff could meet you and your DD fortnightly to hand over any work and be updated about your daughter's progress.
As for private tutors, school is a good place to start. Some teachers offer private tuition as well.
My daughter has been off school since the start of the academic year with anxiety issues. We are now slowly seeing some improvement. School seem to think they are doing all they can but I don't. In four weeks we have had three pieces of work, when I take work in to be marked it takes ages to come back to us. I have asked if my dd can have regular meetings with her teachers (we have met with some and they were happy to do this) - is this a reasonable request? Also, where would I look to find a private tutor as I am worried about how much work she has missed? Any comments would be appreciated.