The Sentinels it's bringing me out the dark

Yesterday had been a grand day in Sarah's life, because she had found a toy! While digging at one end of the den, where the sand was softer, she had hit a small, white, aged shin-bone of what once had been a rabbit. The bone was so old that it did not hold any particular smell to it, both ends were chewed off already - so from every aspect this was not a useful thing, yet in the little girl's eyes it was a treasure. 

She had played with it on her own and had growled at any attempt her siblings might have made to take it or even sniff it. That night she had slept with it tucked tightly against her chest and in the morning, after having her breakfast, she had picked up her bone and decided to take it outside. She set in on den's doorstep, looked first at the surrounding area then down to her toy. "Wruff!" she barked at it, as if telling something important to it.