Theory:

     Soon Lalli went in to tell her mother. Rukku Manni appeared, looking harassed, with Paati following her.

     “Where could they be? It’s really quite upsetting to think someone might have stolen them. So many vendors come to the door,” worried Paati.

     Rukku Manni caught sight of Ravi, Mridu, and Meena sitting under the tree. “Have you children...” she began, and then, seeing they were curiously quiet, went on more slowly, “seen anyone lurking around the verandah?” A sharp V-shaped line had formed between her eyebrows. Another straight, tighter one appeared in place of her usually soft, pleasant mouth. Rukku Manni was angry! thought Mridu with a shiver. She wouldn’t be so upset if she knew about the poor beggar with sores on his feet, she tried to tell herself.

     Taking a deep breath, she cried, “Rukku Manni, there was a beggar here. Poor thing, he had such boils on his feet!”

     “So?” said Rukku Manni grimly, turning to Ravi. “You gave the music-master’s chappals to that old beggar who turns up here?”

     “Children these days...!” groaned Paati.

     “Amma, didn’t you tell me about Karna who gave away everything he had, even his gold earrings, he was so kind and generous?”

     “Silly!” snapped Rukku Manni. “Karna didn’t give away other people’s things, he only gave away his own.”
 
    “But my chappals wouldn’t have fitted the beggar’s feet...” Ravi rushed brashly on, “And Amma, if they did fit, would you really not have minded?”

     “Ravi!” said Rukku Manni, very angry now. “Go inside this minute.”
Explanation:
  
Lalli went inside the house to inform her mom about the music-master's missing chappals. Rukku Manni came outside, looking stressed out. Paati also came along with her; she wondered where they could be. She said it was very disappointing to know that some vendors who come to the door might have stolen them.
 
Rukku Manni just then saw the children. They were sitting under the tree. Just as she started to ask "Have you children...." she stopped the sentence halfway because they were unusually quiet. She continued slowly and asked if they had seen anyone hiding in the verandah. She suspected that the kids had done something to the chappals. A sharp V-shaped line had formed between her eyebrows, meaning she became angry and strict.
 
angry.png
Rukku Manni's eyebrows took a V shape, in anger!
 
The usually soft, good-natured mouth of Rukku Manni had become another straight tight line. Mridu shuddered at the thought that she was angry. Mridu convinced herself that if Rukku Manni knew what they did with the chappals, she wouldn't be very upset. Mridu took a deep inhale and started explaining the truth. She said there had been a beggar there with a lot of boils on his feet. Rukku Manni turned to Ravi and asked him if he gave the chappals to the beggar.
 
Paati started grumbling that "children these days..." and stopped. She meant to say children these days did things without elders permission, unlike the children of her era, who were obedient and not as mischievous.
 
Ravi had a reply, and he asked his mom that she had explained about the kind and generous Karna, who had given away everything he had, including his gold earrings. (Karna is a character from the great epic Mahabharat, who was known for his generosity). Rukku Manni replied angrily that Karna had not given away other people's things, he had given his own things only.
 
Ravi continued rashly to say that he would have given his chappals, but it wouldn't have fit the beggar's feet. He added another question, much to the irritation of his mom - whether she would have minded if he had given his own chappals in case it had fit the beggar.
 
Rukku Manni choose not to answer the question as she was very angry, she just ordered Ravi to go inside immediately.
Meanings of difficult words:
 
No.
Words
Meanings
1
harassedfeeling tired due to having to many demands, stressed out
2
lurking
remaining hidden, like ready to attack
3
brashlyrash, energetic quality (of a young man)
Reference:
National Council of Educational Research and Training (2007). Honeycomb. A Gift of Chappals - Vasantha Surya (pp. 18-32). Published at the Publication Division by the Secretary, National Council of Educational Research and Training, Sri Aurobindo Marg, New Delhi.