gee Steve, that is a little difficult to follow.
You have ..
Emma Robinson was born 1865
Avera Georgina May Matusky born 1862, Prussia
Emma Corney born 1834 married 1852 to George Robinson

So..
Adolph Matusky married Avera Corney in Prussia
a daughter Avera Georgina May Matusky (1862-1926) married William John Armstrong and had 7 sons & 2 daughters, one of them being your John Thomas Armstrong (1885-1964)
Are you thinking that Avera may have used the name Emma? If so, who is the Emma Corney born 1834?

thanks for your reply ngairedith ,
i am thinking emma robinson b 1865 changed to avera matusky .
her mother was emma corney b 1834 married george robinson.
yes very tricky one . the dna matches i have on "my heritage" and "ancestry" of 2nd ,3rd and 4th cousin,all point to the "emma corney married george robinson in 1852".
i have contacted several of them , none can find a family link to my armstrong family in their tree.i do have other armstrong kin with the same dna links from william and avera ,so clearly the link is avera georgina may matusky.
my main theory is .avera g m matusky is emma robinson b 1965 who disappears from the history of all my robinson dna matches.
how to find out ?
cheers
steve

I would like to let you know what I found Avera georgina may Matusky, parents were Adolph matusky and avera matusky she was born Corney she had a sister emma robinson corney who was born in 1834 and died in new zealand in 1916 looks like they came out on the john seymour . Avera the daughter married William John in 1882 and they had 10 children once again one of the daughters had Avera as a second name.Emma would have been the aunt so thats why it showed up in the d.n.a