Umm al-Fadl reported: A bedouin came to Allah's Apostle (ﷺ) when he was in my house and said: Allah's Apostle, I have had a wife and I married another besides her, and my first wife claimed that she had suckled once or twice my newly married wife, thereupon Allah's Apostle (ﷺ) said: One suckling or two do not make the (marriage) unlawful.
Umm Fadl (Allah be pleased with her) reported that a person from Banu 'Amir bin Sa'sa said: Allah's Apostle, does one suckling make the (marriage) unlawful? He said: No.
Umm Fadl (Allah be pleased with her) reported that Allah's Apostle (ﷺ) said: Being suckled once or twice, or one suckling or two, do not make marriage unlawful.
In the narration transmitted on the authority of Ibn Bishr there is a mention of two sucklings and Ibn Abu Shaiba has narrated it with a small variation of wording.