There are two Tanner households 1870 census Dade Co, MO.I would say they are related, note 2 are blacksmiths.Emma could be in either household, "mother" in either hh was born MO, neither "father" was born MO, but this will give you something to watch for.
Tanner, Meredith, 24, b AR - Blacksmith " Jane, 18, b MO " Clarissa E., 4/12, b MO (could "E." stand for Emma?) " William, 60, b TN " Nancy 48, b KY
Page 96, handwritig is not clear:
Tanner, John, 50 b IN - Blacksmith " (Christiana?), 39, b MO "First letter clearly is "E" and "could" be Emma, 2, b MO Bradshaw, M.J., 14, b MO
Thought I might see if any of the above were on the 1880 census, guess who I found in Hill Co, TX on same page as your "Calwin?" I would say indexer really had difficulties reading the names on that page.Little Clarissa/Clersa is in the household, so that eliminates her as "possible" Emma:
Maridy TANNERSelfMMaleW29ARFarm LaborerKYKY Janae TANNERWifeMFemaleW25KYK. HouseKYKY Clersa TANNERDauSFemaleW8MOARKY Casa TANNERDauSFemaleW3MOARKY Florences TANNERDauSFemaleW2TXARKY William TANNERFatherWMaleW83KYHomeALAL Wiott TANNERNephewSMaleW8MOHomeMOMO
The 1880 census on the FamilySearch site shows several Tanner families in Hill Co, TX.Can't tell if any of the others are related to Meredith/Maridy.