Where does “maattuška” come from?

maattuška (Ingrian) comes from Russian ма́тушка, from Russian мать, from Old East Slavic мати, from Proto-Slavic mati, from Proto-Balto-Slavic mā́ˀtē, from Proto-Indo-European méh₂tēr — mother.

Ancestry of “maattuška”, step by step

Step	Language	Word	Meaning
1	Russian	ма́тушка	mother, mum
2	Russian	мать	mother
3	Old East Slavic	мати	mother
4	Proto-Slavic	mati	mother
5	Proto-Balto-Slavic	mā́ˀtē	mother
6	Proto-Indo-European	méh₂tēr	mother

Every word from Proto-Indo-European méh₂tēr →Every word from Proto-Balto-Slavic mā́ˀtē →Every word from Proto-Slavic mati →