Peter E. Nelson was born in 1881 and died 8/24/1948 in Crosby, Crow Wing, Minnesota. Parents - Swen Nelson and Ingrid Hoffstrand.
Source: https://familysearch.org/pal:/MM9.1.1/FDXQ-7GX Doesn't look like this Ingrid Hoffstrand is the one that married your Swen.
1910 Deerwood, Crow Wing, Minnesota census
Sven Nelson, 58, married 28 years, born in Sweden, came to US in 1888 Ingrid, 55, born in Sweden, came to US 1890 Nels, son, 30, born in Sweden, came to US 1890 Peter E, 28, born in Sweden, came to US 1890
1900 Stillwater, Washington, Minnesota census
Swen Nelson, born 11/1850 in Sweden, married 23 years, came to US in 1888 Ingrie, brn 10/1854 in Sweden, came to US in 1890. 6 children, 5 living. Nels, born 10/1879 in Sweden Peter, born 8/1881 in Sweden Andrew, born 7/ 1883 in Sweden Ida, born 5/1886 in Sweden Harry, born 2/1893 in Minnesota