Raymonde Miessan, 39, and husband Kacou, 45, originally from the Ivory Coast now live in Ashford, Kent.
In February they were given 12-month jail terms after pleading guilty at Canterbury Crown Court to assisting unlawful immigration.
The three appeal judges ruled the pair should serve five months.
They said the couple’s motive had been to adopt a child and there was no suggestion of trafficking.
The judges said the evidence showed he had been well cared for by the couple.
The boy is now in local authority care.
BBC © 2013