I'm writing a ghost story, and (in an admittedly well worn trope) a child ghost is looking for its mother; but how would a 17th century child affectionately refer to its mother? In short, what would the 17th century version of "mummy" be?
British English \mə-ˈmä\
(American English \ˈmä-mə\ or \məˈmɑ)
mama (also, mamma) nursery word, with parallels in other European languages, probably in part inherited or borrowed, in part newly formed; compare Latin mamma, Greek mámmē breast, mama, French maman, Welsh mam mother
Etymology Dictionary says mamma, (spelled with a double -m), is dated in 1570s
representing the native form of the reduplication of *ma- that is nearly universal among the Indo-European languages [...] Its late appearance in English is curious, but Middle English had mome (mid-13c.) "an aunt; an old woman," also an affectionate term of address for an older woman. In educated usage, the stress is always on the last syllable. In terms of recorded usage of related words in English, mama is from 1707, mum is from 1823, mummy in this sense from 1839, mommy 1844, momma 1852, and mom 1867.