Doesn't matter. They see the grades on your transcript.

It only matters for reporting non-school anguages that you know.

You check of speak, read, write, first language, or spoken at home.

I’m guessing this is an outdated blog.

Ask her in her Facebook group?

Yes always write proficient if they took years of the language in HS, or fluent if native near native.

What did your kids answer?
Did you list a language that your kid takes in HS if it's something like Latin?

"The Common App asks students to indicate how many languages they are "proficient" in, which ones, and to what extent. Note the word "proficient." That is different than "fluent." Most students can select English and the language they take in high school. Some students can select English, the language they take in high school, and a native language spoken at home. The checkboxes allow the student to choose a number of levels of proficiency from speaking to reading, writing, and more. Don't be afraid to list the languages you are proficient in. It speaks to your heritage and/or your linguistic range. And if you don't see a language, select "Other" and type it in!"

https://www.saraharberson.com/blog/trickiest-questions-common-app