Umm al-Fadl reported: A bedouin came to Allah's Messenger (ﷺ) when he was in my house and said: Allah's Messenger, I have had a wife and I married another besides her, and my first wife claimed that she had suckled once…
Umm Fadl (Allah be pleased with her) reported that a person from Banu 'Amir b. Sa'sa said: Allah's Messenger, does one suckling make the (marriage) unlawful? He said: No.
Umm Fadl (Allah be pleased with her) reported that Allah's Messenger (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.
Umm Fadl (Allah be pleased with her) reported Allah's Messenger (may peace be'apon him) having said this: One or two sucklings do not make (the marriage) unlawful.