Is it not seanmháthair?
They also use mama for it in Japanese, but I don’t know the history behind it so it could be an imported word.
Happy fed baby sounds.
Mandarin Chinese = Mama
Interesting note, in that language, “ayee” is “auntie/aunt”
Actually, my baby uses “mama” when he’s hungry and wants his mom (or, more specifically, the boob that is attached to his mama).
The hungrier, the more repetitions of the syllable “ma”: “Mamamamama.” 
Swahili: mama
Polish: Mama, Matko (Mother)
Arabic: Mama, Oum (mother in the non possessive. If possessive: Oumi)
Filipino: Inay
Latin: mother = mater. Breast = mamma. So that indicates either not knowing how to count or wishful thinking.