Professor McGonagall knew Ginny was taken in because she wasn't seen for long and when the message "Her body will lie in the chamber forever" came, she was the only Gryffindor who wasn't anywhere in the dormitory
.
It is never actually explained how Professor McGonagall knew that Ginny Weasley was the one taken. Due to the attacks the school was being very strict about security, so it is likely Ginny was the only student unaccounted for on the class registers.
Chapter Fourteen - Cornelius Fudge.
Ron Weasley.
No. She can't speak Parseltongue, the snake language needed to open the chamber. Ginny Weasley opened it. Ginny could speak Parseltongue because Voldemort was possessing her through the Diary and speaking Parseltongue in her mind.
Ginny Weasley, who was being possessed by a horcrux of Lord Voldemort.
Yes, Fred and George Weasley appeared in every Harry Potter.
When the Chamber of Secrets were opened.
Chapter Fourteen - Cornelius Fudge.
When Ginny Weasley is taken into the Chamber of Secrets.
In Chamber of Secrets, Tom Riddle's diary possessed her and forced her to open the Chamber of Secrets.
Ginny Weasley.
Ginny Weasley, Ron's sister.
Ginny took herself into the Chamber of Secrets, as instructed by Lord Voldemort who was possessing her at the time.
Ginny Weasley.
To rescue Ginny Weasley.
yes,
Ron Weasley.
To save Ginny Weasley.