Brief Answer:
Please get her clinically evaluated by a physician

Detailed Answer:
Hello

I can understand your concern.
Pain in lower left side of abdomen can be due to muscle pull, blunt trauma to inner abdomen or less commonly due to bony injury.
The most likely cause here is muscle pull(sprain) as bony injury causes restriction of limb movement and blunt trauma to inner abdomen is mostly associated with vomiting and or constipation.
Giving analgesic with muscle relaxant and hot foment action helps in relieving muscle spasm but first get her clinically evaluated by a physician to rule out any significant problem.

I hope this helps
Wishing for your child's good health.
Please let me know if you have any more queries.
Regards

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Brief Answer:
Details below

Detailed Answer:
Thanks for follow up

Internal injury to abdomen is usually associated with fullness of abdomen, greenish vomiting, difficulty in passing stool and is usually constant in nature. While sprain or muscle spasm is more with change in posture.
Observe her and if pain is severe, she is getting pale, very irritable/anxious or if the palms/soles are getting cold (signs of internal bleed) get her to the emergency room.

Regards

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