Hi Jill,
This is fantastic news.

Here is the link to Arthur’s marriage record:

Østfold fylke, Halden, Klokkerbok nr. 11 (1906-1934), Ekteviede 1916, side 49.
http://www.arkivverket.no/URN:kb_read?idx_kildeid=387&id...

Reidar’s baptism record:
Østfold fylke, Halden, Klokkerbok nr. 10 (1900-1923), Fødte og døpte 1917, side 191. http://www.arkivverket.no/URN:kb_read?idx_kildeid=4899&i...
Born 15th of August 1917, baptized 16th of September 1917
Reidar Marinius
Parents: Arthur Marinius Valeur, born 1893 and wife Jenny Mathilde maiden name: Hansen, born 1894
Address: Øvre Bankegd.
Godparents: Plan mill worker Karl Valeur, unmarried girl Valborg Hansen, the parents

Østfold fylke, Halden, Klokkerbok nr. 10 (1900-1923), Fødte og døpte 1920, side 217. http://www.arkivverket.no/URN:kb_read?idx_kildeid=4899&i...
Born 4th of January 1920, baptized 22nd of February 1920
Kaare Emanuel
Paretns: Arthur Marinius Wallør, born 1893 and wife Jenny Mathilde, maiden name Hansen, born 1894
Address: Ø. Bankegd. 5
Goodparents: widow Mathilde Hansen, Miss Valborg Hansen, Anders Hansen, the father

Østfold fylke, Halden, Klokkerbok nr. Ga 0012 (1923-1946), Fødte og døpte 1923, side 6. http://www.arkivverket.no/URN:kb_read?idx_kildeid=7360&i...
Born 23rd of June 1923, baptized 15th of July 1923
Gudrun Helene
Parents: Arthur Marenius Valeur, born 1893 and wife Jenny Mathilde, maiden name Hansen, born 1894
Address: Ø. Bankegd. 6
Goodparents: widow Mathilde Hansen, Mrs Valborg Karlsen, the childs father, Marinius Karlsen

I’ve looked through 1928 without finding any other children.

Jenny Mathilde’s baptism:
Østfold fylke, Halden, Ministerialbok nr. I 13 (1890-1906), Fødte og døpte 1894, side 74. http://www.arkivverket.no/URN:kb_read?idx_kildeid=4897&i...
Born 18th of September 1894, baptized 14th of October 1894
Jenny Matilde
Parents: Jens Marinius Hansen, born 1866 and wife Matilde, born 1861
Address: Høvleriet
Goodparents: Hans August Hansen, ? Augusta ?, Karl Einar Hansen, the childs mother
The parents have 3 children

So far unsuccesfull to locate Jenny in the census of 1900.

Regards,
Arna