(This is a post from my old yahoo group which I have reworked. The original question had to do with suggestions for hiring a Waldorf teacher to work with a mixed age Waldorf co-op).
To be perfectly honest, this is an area where I see many, many problems - I see situations where groups/co-ops hire a Waldorf teacher and it often becomes a disaster. And often for the reason you describe - the teacher, because of a rather narrow and classroom focus on Waldorf education, is unwilling/unable to work with mixed ages.
IMy opinion is that any group who wants to bring in a teacher or advisor needs to be absolutely clear that they are first and foremost homeschoolers - that their children are not not in Waldorf schools simply because, for whatever reason, it hasn't been possible. Even if that is so for some folks, I would advise that they think carefully about that mindset because it can seriously undermine one's confidence and abilities as a homeschooler.
This can also be the case with a group. If the teacher is disapproving - because people don't quite follow the curriculum or add in things from other educational methods, or combine children or have no problem with 10 year old non readers, then this can wreck havoc! I have seen this a lot!
I would suggest, as I said in the first paragraph, that this is mainly down to the fact that the person has been trained for a Waldorf classroom situation and because s/he is unfamiliar with homeschooling - and how vastly different it is. I spend more and more time in workshops I give - and considerable time in my books - explaining that one simply cannot transfer classroom methodology to a home situation. With groups it is somewhat different - but the exciting challenges (for the Waldorf teacher) mainly have to do with the realife family situations they face - ie mixed age children.
So I often gently advise people to think long and hard before hiring a Waldorf teacher to work with their group. If that person's role is to teach parents handwork, painting and other skills so that they can bring this to their children - then great! But if that person and the Way Things Are Done becomes the main focus for people's homeschooling - and, more importantly, a measuring stick of how they "perform" at home - then I say Beware! This can be so undermining! You homeschoolers - all of you - need to be enabled and empowered to create your own homeschools! Bottom line!
Having said all that, there are certainly examples of a Waldorf teacher working with a group and this being a great thing. Often, I have seen, parents drift off after a while, having gotten what they need from that person's guidance and then being able to create the forms themselves. And sometimes that Waldorf teacher's motive has been to eventually create a new Waldorf school - and I've seen where that becomes wonderful for the parents who want the school and not so great for the ones who prefer to homeschool! An example of where I saw a Waldorf teacher working with homeschoolers very succesfully - and with mixed age children - is in Minneapolis, where a eurythmist holds weekly sessions for homeschoolers which are apparently both popular and enormously beneficial.
My suggestion is that you get advice from someone like me or Barbara Dewey (Waldorfwithoutwalls) who understand (and in my case is a ) homeschoolers. I can help talk through how a group can work together and create their own unique group or co-op as they explore both Waldorf and homeschooling.
I feel rather strongly about this. I taught in a small Waldorf school in England where we combined children in many different ways. Although this was considered not ideal by several of the teachers, as far as I could see, the benefits far outweighed the drawbacks. And from my deep study of Waldorf education, I also see where Steiner was more than clear that there are possibilities for combining children (see my Curriculum Overview for more on this). And I also spend an awful lot of time repairing damage done - both to individuals and to Waldorf education as a whole I feel - by narrow people who have a rather limited way of working with Waldorf and an uncreative way of expressing that to parents!