That is really odd advice your school counselor gave you @coffeeat3. My kid has been in creative writing camps since 4th grade and was able to learn how to give and receive criticism as an elementary school kid. I really see no point in waiting.
Hollinsummer is a great supportive environment, but it’s also at a school with a top notch Creative Writing program. You will see Hollins listed on many of the “best schools for creative writing” lists. There were 9th graders when my daughter attended and there was probably a bigger disparity in ages that year because it was 2021 and they were not able to run the program in 2020 when my daughter was first signed up to go. I think there were a lot of kids who ended up there in 2021 as rising seniors and juniors and sophomores when they might’ve come in 2020.