The sentence you wrote is mostly correct! Here's the original sentence:
The penguin dad gently holds the egg on his feet, tucked away in his feathers, while the mother is off catching fish for her family.
It sounds clear and grammatically good. Here are some helpful points:
- Subject and verbs: "The penguin dad gently holds" is correct because "dad" is singular, so we use "holds."
- Phrase about the egg: "on his feet, tucked away in his feathers" describes where the egg is. This is a nice description and fits well.
- While clause: "while the mother is off catching fish for her family" is also clear. "is off catching" means she is currently gone to get food, which makes sense.
If you want, you can also say:
The penguin dad gently holds the egg on his feet, tucked safely in his feathers, while the mother goes off to catch fish for her family.
But your original sentence is perfectly fine for a 7-year-old to understand!