Her eyes appear to be glass. She comes with the clothes shown in the pics, but I don't know if they are her original clothes. They were found packed together.
Here is some information I obtained from the internet. "Fritz Bartenstein Dolls 1880 -1905 Germany". Fritz Bartenstein an inventor and doll factory owner was first employed in the doll industry at Schoenau Porcelain doll factory in 1864.By 1880 he filed his first patent for a multi-faced doll with a pull string inside the head that turned the faces housed inside a hood and a second string inside the torso that simultaneously made the doll cry Mama, as shown in the two patent drawings on left. Doll socket heads are made of wax, composition or bisque with two doll faces laughing an another crying, in white dolls or black or a white face and a black face. The item "ANTIQUE FRITZ BARTENSTEIN TWO FACED DOLL BISQUE HEAD DEUTSCHE REICH 248762" is in sale since Friday, September 30, 2016. This item is in the category "Dolls & Bears\Dolls\Antique (Pre-1930)\Other Antique Dolls". The seller is "4u2love" and is located in South Plainfield, New Jersey. This item can be shipped to United States, to Canada, to United Kingdom, DK, RO, SK, BG, CZ, FI, HU, LV, LT, MT, EE, to Australia, GR, PT, CY, SI, to Japan, to China, SE, KR, ID, to Taiwan, TH, to Belgium, to France, to Hong Kong, to Ireland, to Netherlands, PL, to Spain, to Italy, to Germany, to Austria, RU, IL, to Mexico, to New Zealand, SG, to Switzerland, NO, SA, UA, AE, QA, KW, BH, HR, MY, CL, CO, CR, PA, TT, GT, HN, JM, AG, AW, BZ, DM, GD, KN, LC, MS, TC, BB, BD, BM, BN, BO, EC, EG, GF, GG, GI, GP, IS, JE, JO, KH, KY, LI, LK, LU, MC, MO, MQ, MV, NI, OM, PE, PK, PY, RE.