Maria Humalalampi (Harju) - Legitimate Children and age of father

I'm very excited to have found a Finnish resource in this genealogy search!

Maria is noted in multiple places as having 5 children total, 3 legitimate with Elias Humalalampi before 1889 and 2 illegitimate after he immigrated to America. I only have record of 4 children:

Aina Maria (Anna Marie) Humalalampi (Lampi) B. 1884, from Karstula, Passport 1903 (w/ sister Elma), in America (w/ mother Maria) in 1910
Emil Humalalampi (Lampi) B. 1887, from Alaveteli, Passport & migration 1904, in America (near Elias) in 1910

Elias immigrated to America in 1889

Questionable paternity:
Kalle Vihtori Humalalampi B. 1889, from Karstula, Passport 1906, migration 1907, not yet found in American documentation
Elma Humalalampi (Stenroth) B. 1893, from Karstula, Passport & migration 1903 (w/ sister Aina), in New York in 1912, Canada in 1913, Michigan 1921

This still leaves one missing child, either legitimate or illegitimate as Kalle could be attributed to either group.