YOU SAID:

I am sitting next to Katie, and Cameron next to her.

INTO JAPANESE

私は彼女の隣に、ケイティとキャメロンの横に座っています。

BACK INTO ENGLISH

I was next to her sits next to Katie and Cameron.

INTO JAPANESE

ケイティとキャメロンの隣に彼女の座っている隣だった

BACK INTO ENGLISH

Next to her sits next to Katie and Cameron

INTO JAPANESE

ケイティとキャメロンの隣に彼女の座っている隣に

BACK INTO ENGLISH

Beside her sits next to Katie and Cameron

INTO JAPANESE

ケイティとキャメロンの隣に彼女の座っている横に

BACK INTO ENGLISH

Beside her sits next to Katie and Cameron