Ms. A and I are both in the same year at the same school, but we've never had a class together.
こんにちは。
ご質問ありがとうございます。
"Ms. A and I are both in the same year at the same school,"＝「Aさんと私は同じ学年で、同じ学校に通っています」
"but we've never had a class together."＝「でも、同じクラスになったことはありません。」
又は、"but we've never been in the same class."＝「でも、同じクラスにいたことはありません。」
ご参考になると幸いです。
Someone in my year who I have never been in the same class with.
"同じクラスにはなったことがない同級生"
- Someone in my year who I have never been in the same class with.
- A 'classmate' who has never been in the same class as me
Ａ子さんとわたしは同じ高校の同級生だけど同じクラスにはなったことがない。
- A and I went to the same high school but we have never had the same class.
アメリカ合衆国 
