Try to find descendants of Lena Gilbertson, ND

Hi! I'm searching relatives in USA. Two of my grandfather's siblings emigrated from Norway to Minnesota and moved on to North Dakota. One of them left Norway in 1900 and the other one in 1904. I have searched the Ellis Island records and different sources through FamilySearch Library and Ancestry.com. I also have some very limited information from my grandfather from the 1950's. I have discoverd that one of the emigrants, Karoline (Lina) Amundsen married a George Gilbertson and got four children. I can follow the family through different US censuses. Sometimes she is also named Lena. I also discovered that one of the four children, Gladys Gilbertson born in 1914, married George Montgomery born in 1910. The marriage took place in 1942 in Glasgow, Montana. After 1940 it is difficult to find records except for death records. George Gilbertson died in 1947 and Caroline in 1954. They are buried at Bethel Lutheran Cemetery in Bergen, North Dakota. This I found in the database of Find a Grave. And by luck I also found a website on faqs.org with People Search. Then I could browse surnames in US death records. I discovered a George Montgomery, birth in 1910 and death in 2001, and a Gladys Montgomery, birth in 1914 and death in 1997. Both had been living in Minot, ND. Her zipcode was 58701 and his was 58702. Maybe he moved after her death. To me this seems to be a possible match. I also found some information on a website for the Montgomery Family. It says that George Montgomery was married to Gladys Gilbertson, and he was active in the Lutheran Church where he was a Sunday School Teacher. But there was no information about her or if they had any children. I have tried to get in contact with some of the churches in Minot, but without any "solution" so far. Does anybody know anything about this family and if there are any descendants? Or has a hint about what to try next? With regards Arne Bråten 2053 Jessheim Norway