business entity family questions

Can a salon hire family members 14 yrs of age?
Can their payroll be placed into a 401k plan tax free? Without offering to other employees? Are there any restrictions
Does the family member need to be a son/daughter or can it be nice/nephew?
Are there any income limits for the 14 yr old/salon?
is it requirement to pay minimum wage?

Thank you for your help

Those are mostly legal questions.

What's the definition of a nice nephew?

Agreed.
There are some tax questions here, but the more important ones are legal and the right answer will depend upon your state.

If you think it through, you might come to the conclusion that it's probably a much better idea to put the 14 year old nice nephew's earnings into a Roth IRA rather a pretax account.

Especially if the earnings don’t exceed for
Example $12,950

Apart from the legal labor law questions, you cannot offer a 401(k) Plan to your relatives only and not other employees.

In NY minors, including 14 year-olds, can work. The issue is the number of hours they can work, which varies with age.
https://dol.ny.gov/hours-work-minors

Those are mostly legal questions.

What's the definition of a nice nephew?

Sorry. meant "niece"

Especially if the earnings don’t exceed for
Example $12,950

Why 12,950?

Why 12,950?

Standard deduction