Why might Ray Bradbury have used Rima as the antithesis of the lions in "The Veldt"?

There are many reasons why Ray Bradbury used Rima as the antithesis to the lions in his 1950 short story "The Veldt." 

Rima is a character created by Wiliam Henry Hudson in his 1904 work entitled Green Mansions. The story is set in the Guyana jungle in Venezuela. The jungle setting itself is the antithesis of the African savannah in which the lions in Bradbury's story dwell. Where the savannah is raw, dry, and unyielding, the jungle is lush, fragrant, and enchanting. 

Rima is a gentle young woman who speaks in a musical, birdlike language, and can communicate with birds. In the book, Green Mansions, Rima chases game animals away, and the local Indians wish to kill her for this. The Indians are predators, and Rima disperses their prey. In "The Veldt," the children are like predators, and Rima is chasing off their prey, replacing the lions that are being trained to destroy their parents. In the following quote from "The Veldt," Bradbury foreshadows the impending plot the children are concocting:

In the middle of the night he was still awake and he knew his wife was awake. "Do you think Wendy changed it?" she said at last, in the dark room.

"Of course."

"Made it from a veldt into a forest and put Rima there instead of lions?"

"Yes."

"Why?"

"I don't know. But it's staying locked until I find out."

"How did your wallet get there?"

"I don't know anything," he said, "except that I'm beginning to be sorry we bought that room for the children. If children are neurotic at all, a room like that -" 

Rima is different from Peter and Wendy in that she enjoyed a very close relationship with her mother for the first seven years of her life. There is no textual evidence to suggest that Peter and Wendy ever had a close relationship with their parents. George Hadley says they never lifted a finger to correct them and, as a result, were "insufferable." 

Another way Rima is an antithesis to the lions is that when she appears in the nursery, she is surrounded by lush, green beauty and purple mountains. There is a river flowing nearby. Rima is hiding in the trees singing a song so beautifully that it moves them to tears. This is the gentle and peaceful scene George and Lydia expected from the nursery. It is in stark contrast to the African Veldt, where the sun is hot and punishing, smells of animals and death pervade, and lions are devouring their prey. 

Another interesting parallel is that in Green Mansions, the character known as Mr. Abel sees a savannah near the jungle and is interested in exploring it. The natives believe the savannah to be haunted and refuse to go near it. This parallels Lydia Hadley's feelings of foreboding in the African Veldt.