Sayyiduna Abdullah bin Umar (may Allah be pleased with them both) said: A slave woman who is married to a slave and is then freed has the choice regarding herself until her husband has intercourse with her.
(b) In Malik's narration there is the addition: If the husband has had intercourse with her, then she has no choice.
Hadith Referenceالسنن الكبرى للبيهقي / كتاب النكاح / 14285