The Senedd in Cardiff is closed for a month from Thursday December 6th. Try for a meeting in the constituency on Friday 7th December or the following week, when your AM might be catching up with constituency business before the holidays.
Otherwise you can book now for an appointment in the early New Year. It should be possible to email all five AMs (constituency and regional) to ask for an appointment for a small group from your local area. Note that a full postal address within the AM's constituency is required, even in email as they'll only deal with their own constituents.
Opening Your Conversation With Assembly Member
1/Our children are home educated because... 2/We have been home educating since... 3/In our home education we have had support from... 4/Our experience of the council has been...[if not known, can say what friends' experience has been] 5/We feel very strongly about the Government's plans for home education because... 6/Our family would be affected by the proposals in the following ways... 7/Current Government Guidelines already cover welfare/safeguarding/standards/diversity/