Are there natural ways to replace HGH in a child?

No. There are no known natural products which replace growth hormone in a growth hormone deficient child. Current growth hormone preparations are artificially manufactured, but bioidentical to human growth hormone.
No. The is no natural way to replace growth hormone in a child who has growth hormone deficiency. In order for additional growth hormone to get into a child's blood and flow to all the parts of the body where growth hormone is needed, the additional hormone must be injected into the skin (usually once a day). Oral "medications" containing growth hormone or hormone-like substances are not effective.
No. Hgh is a safe and efficient treatment to improve final height in children that have a medical indication for its use.