This is a reported case arising out of the divorce. Calvin and Ella agreed to $2.50 per week in child support for the child, Sidney Athol Ward, Sr. Calvin appealed from a judgment awarding Ella the money. From what it appears, the divorce did not include the child support. The Colorado Supreme Court affirmed the judgment in Ella's favor for the money finding adequate consideration for the contract.
From a lawyer's point of view, this is a fascinating fact pattern. It formed part of the discussion of contract law for years to come getting noted in Harvard Law Review, 1905-06; "Problems in the Law of Contracts" Ballantine 1915; "Corbin on Contracts" 1950. The case is cited in Farnsworth's Contracts.
I wish I had known in 1983 when I read principle and the cite. I wish I still had my contracts text. I believe that I used Farnsworth for the then current edition. Oh well. It is still available.