Looking for Ohlson of Minnesota Manitoba

Lars and Maria OHLSON, had 4 children born in Minnesota USA. (The girls were baptized in Farley, Polk County)
Katie, Anna, Emma and John (1888-1894)
They moved to Winnipeg Manitoba, Canada and had another daughter Elsie 1896. Maria died within a year of giving birth to Elsie and it is believed that Lars died in a construction accident about one year later.
The children were put in an orphanage and later fostered to separate homes.
The children remembered an Uncle Gilbert, but we don't know if he was family or friend.
We never heard Maria's maiden name.
Can anyone help??