Theory:

     I knocked and entered. The captain was standing in the middle of the room. When he saw me, he came forward and literally swept me off my feet. He was still smiling when he put me down.

     “You will have plenty to tell your friends, eh? Now close your eyes.”

     I did so. Seconds later, I heard him say, “See what I’ve got for you.”

     On opening my eyes, I saw a big brown box. On it was written: “WITH THE BEST COMPLIMENTS OF CAPT. LINDSAY.”

     I took the box and eagerly opened it. “Oh, what a lovely ship!” I exclaimed. “Does this really belong to me? Can I keep it?”
Explanation:
 
The little girl was quite excited to meet the captain, and she was also reminded of the captain's words that some surprise was waiting for her. She knocked on the door and entered the captain's room will full of excitement. While she entered the room, she saw the captain standing over there.
 
When the captain saw her, he went near her. He picked her up in joy and put her down with a smile on his face. He told her that she would be having so much to say to her friends regarding the sea incident.
 
Then the captain asked Vasantha to close her eyes; he wanted to show her the gift he had planned for her. She closed her eyes as instructed by the captain. After a few seconds, she heard him saying, "See what I've got for you."

With great excitement, Vasantha opened her eyes. There was a brown box placed before her. On it was written: "WITH THE BEST COMPLIMENTS OF CAPT. LINDSAY." Vasantha couldn't express her happiness. She was too eager to open the gift. When she opened the box, she was surprised to see a stunning miniature of a ship. Her beautiful eyes widened in wonder, and she exclaimed, "Oh, what a lovely ship!" She then asked the captain, "Does this really belong to me? Can I keep it?" She asked him the questions as she couldn't believe that the marvellous gift was for her. These questions also reveal the childlike qualities of the girl.
 
Meaning of difficult words:
  
S.No
Words
Meaning
1.
Compliment
A comment or statement that shows praise of approval
2.
Exclaim
To say something suddenly and loudly because of strong emotion or pain
Reference:
State Council of Educational Research and Training (2018). Term-3 English Standard-7. Man Overboard - Vasantha Murthi (pp. 125-130). Published by the Tamil Nadu Textbook and Educational Services Corporation.