Answer: You are correct. The McKinney-Vento Act applies to charter schools. The school must provide transportation to the school of origin for the child, as long as continuing to attend the school of origin is in the child’s best interest.
As far as approaching the situation, you definitely should contact your state coordinator first, to ask for her assistance. It would be very good for her to know about this situation, so that she can step in if necessary. You also might reach out to the liaison for your school district, who might have a working relationship with the charter school, and who might be able to step in to help pave the way for a conversation.