Theory:

     Where do you go to school?” types Shree.
 
     “Near your school,” types Chaitra.
 
     “How do you know which school I go to?” wonders Shree.
 
     “Because it is near my school.”
 
     “That’s nice. Then we can meet,” types Shree.
 
     Chaitra signs off. “Yes! And we’ll be best friends forever. Bye!”
Explanation:
 
Shree then began to inquire about Chaitra's school. When Shree asked about Chaitra's school, Chaitra replied that it was close to her school. Shree was taken aback, thinking how Chaitra knew about her school's location. Shree asked her the same question right away as to how did she know about it?.
 
Chaitra's reply to Shree's question was much confusing. She said that she was aware of Shree's school because it was close to hers. Shree asked the right question but was puzzled by Chaitra's answer. Chaitra didn't answer her correctly. It was unclear if Chaitra had already seen Shree near her school or had learned about her school's details from the internet.

Shree was overjoyed and messaged Chaitra to meet because their schools were so close, but Chaitra didn't respond about meeting near their schools. She said 'Yes,' but her focus was once again on building a friendship bond. She texted Shree that they would be best friends forever, showing Chaitra's intention to build intimacy with Shree.
 
Meaning of difficult words:
 
S.No
Words
Meaning
1.
Sign off 
To conclude
2.
Puzzle
Something that is difficult to understand
3.
IntimacyA close personal relationship
Reference:
State Council of Educational Research and Training (2019). Term-3 English Standard-8. The Mystery of the Cyber Friend(pp. 134-139). Published by the Tamil Nadu Textbook and Educational Services Corporation.