Besides the other persons error's, there are many error's found in the posted Brauer family tree identified. For example, it shows daughter Katherine (born in Montana to father born in Missouri, being in Teton County, MT in the 1920 Census, when in fact she was in Fremont County, WY. It also shows Katherine in the 1930 Census in Windsor, Colorado, when in fact this is the family of Jacob Kindsfather, her former Father-in-Law. This proves you can NOT reference someone's online family tree without reviewing it for errors and sources.
It appears you have a good knowledge of the children and you are specific in looking for information on George and Katherine (Hoffman), so I won't compound the issue correcting/finding information on the children. You also appear to be the source of information posted on the other persons family tree, so you might be able to correct some of their errors.
I know you probably have the below, but will post so there is no further mistakes on the main two persons, George and Katherine (Hoffman).
The 1920 Census for Election District 10, Fremont County, WY.
George Yeager(written as Yerger), age 41, born in Russia (German ancestory), immigrated in 1906, "Pa"(indicates he had filed his papers, his Declaration of Intention to become a citizen.
Katie, wife, 35, imm 1906
Katie, dau, age 13, born in Russia, imm 1906
George, son, 11, born in Kansas
Jacob, 9, born in KS
David, 7, Colorado
Libby, 3 9/12, CO (Census enumerated 2-8 March, so Libby would turn 4 about June).
--Family on same sheet:
Jacob Kinsfater(as spelled), 43, born in Russia (German Ancestry), imm 1911, "Pa",
Anna, 44, Russia, 1911
Jacob, 13, Russia 1911
Frieda, 6, CO
Lida(?), 5 9/12, CO
Lena, 9/12, WY
---Based on their Russian residency and German Ancestry, they "might" have been Mennonite. There was a large population of Mennonites that to avoid religious persecution in Germany, which included military service, escaped to Russia. Then in later years, they began receiving the same in Russia, to include mandatory military service, so they came to the US in DROVES.
The 1910 Census for Lakin, Kearny Co, Kansas
Yaeger(as spelled, transcribed as Jasper), George, 30, born in Russ/German Ancestory, immigrated 1908(probably more accurate than the 1906 date in the 1920 census due to birth of Katie/Katherine), "Al"Alien, Contractor/Thining Beets, marriage first/five years.
Katharina, 26, mother of 2/2 living
George Jr, 1 5/12.
Montana Death Index confirms:
George Yeager, death on 12/8/1965, 6200(file number), 24(Lake County).
Katherine Yeager, death on 9/3/1958, 80(file number), 24(Lake County)
--It also showed a George L, Yeager, died 1963 in 37(Pondera Co), used for elimination purposes on below:
I checked the Bureau of Land Management database of land patents issued under the Homestead Act. I found a George L. Yeager being issued land in 1931 and 1939 in Pondera County, but per above, wrong person. Other land issued to George Yeager's were prior to 1920 when the family was in Wyoming. No Yeager found in Lake County receiving land.
The 1930 Census for District 31, Grass Valley, Missoula County, MT
George Yeager, Jr., age 21, born in the US to both parents born in Russia, laborer/farm, married age 19
Catherine, age 20, born in MT to both parents born in Russia
Betty, dau 1 3/12.
--Here is their son, George, born in October:http://www.findagrave.com/cgi-bin/fg.cgi?page=gr&GSln=ye...
In the 1930 Census, other than finding son George, I could not find George and Katherine in Lake County using ANY technique (first name only, Russia only, year of birth plus/minus 5 years, etc.). The 1930 Census showed 9,690 persons enumerated; but with the size of the county, possible absences due to travel, missed farms/residences by the enumerator, it is very easy to not have them found. I quite often run into missing persons in the 1930 census, especially in Montana.
I checked online books and other references, genealogical websites, cemetery transcription sites (cemetery transcriptions across the country are either not done, incomplete, etc.). Also did some checking on immigration for Yeager, Yager, Yaeger, Jaeger, etc., Georg, George, Jorge, etc. There is very limited genealogical activity in Lake County. I aso did some immigration records looking for their arrival in the US, but nothing found.