It in fact does exist. You can't spin-away a child's enjoyment of a contract, conspicuous for over a thousand years.
But all that has been thrown out the window by the SCOTUS and only a Constitutional amendment can restore it.
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Except a new challenge that overturns it based on the fact that two of the Justices were biased going into Obergefell and that Obergefell made a policy of divorcing children from a contractual enjoyment they had for over a thousand years without children having representation at that Hearing, and that children cannot be deprived of a necessity in contract even if they were present and agreed themselves. Also, New York vs Ferber (USSC 1982) Found that even if a person has an explicit and delineated constitutional right, if that right impinges on children's mental or physical well being, that right must not be exercised.
No Constitutional Amendment needed. However, there would be a Constitutional Amendment needed to find people doing weird sex stuff were also anticipated in the 14th Amendment. There is no wording protecting sexual behaviors in the 14th. Also, there's no wording in the 1964 Civil Rights Act that says "men who are pretending to be women have the civil right to do that and to force others to play along".