Sayyiduna Umar ibn Khattab (may Allah be pleased with him) or Sayyiduna Uthman ibn Affan (may Allah be pleased with him) gave the ruling: If a woman deceives someone by saying, "I am free," then marries and has children, and afterwards it is discovered that she is someone’s slave-girl, then by giving a slave-boy or slave-girl like her children, he can ransom his children.

Imam Malik (may Allah have mercy on him) said that in my view, giving the price is better.