I doubt Adelheide/Adele remarried.She is ZANGER/SANGER etal 1900-10-20-30 census, and this is also her name as the informant on Wm's death cert....she would've been 70 yrs old at this time.She gives her b/date as 6-1870 on the 1900 census;August/Gustav/Gust gives his b/date as 2-1867.He says he emi 1889, but the only one found emi 1891...he was a gardener, which might fit his profession as a florist 1910. I, too, could not find obit/death cert for Adele. Since there were no descendents, what is the relationship to you? Researching SCHORSCH records of Alsace-Lorain look to be in order.Best wishes in your quest.
Phyl....volunteer ps the Adelaide SAENGER who m NAPPER is the d/o Wm P SAENGER [d 1967].