The similarity of words for mother in languages not usually thought of as historically closely related, such as Malayalm (and other Dravidian languages, Tamil, Kannada, Telegu) and Indo-European languages (such as English, Latin, Sanskrit, Russian, etc.), is that there is something about labiality sounds such as m, p, and b are bilabials) and suckling. (Please note that I am not advocating this position, just reporting it.) An exception in Hindi is maamaa 'maternal uncle'.

An important and, to my mind, true quality of languages in general is the arbitrary nature of the relationship between a word and the concept underlying it (or if you will, the thing to which it refers). Saussure was the first to state this.

Ceci n'est pas un seing.