No your child's Social Security is not taxable. You do not enter it on your tax return. Someday, if your child also has some other income---like an after school job--- she will enter that SSA1099 on her own tax return with her own income. Until then, it does not get entered on anyone's tax return. You do not pay tax on your child's SS.
**Disclaimer: Every effort has been made to offer the most correct information possible. The poster disclaims any legal responsibility for the accuracy of the information that is contained in this post.**