Thank you for the responses! When I originally spoke to the principal about my concerns, she was incredibly responsive and eager to take action. She was the one who first mentioned making the move to first.

While I'm concerned that K is moving too slowly in some respect, I was also worried that missing four months of first grade would put her behind the class which would be discouraging. She is perfectionistic and can sometimes give up easily if she thinks something is hard. And I don't want to squash her love of learning!

After speaking with the teachers and the learning specialist, they will do some standard and informal assessments before making a decision about how to proceed. This feels reasonable. I will let you know what we decide. Thanks again!