Not sure what you have or don't have so here is what I found.
DEATHS - B.C. death registrations 1872-1986
NEVA HAMPTONage 55
died Nov. 22, 1951 Cloverdale, B.C. Canada
born April 21, 1896 USA
parents David Henry and Bertha Page
husband Edward Milton Hampton
she is listed as married so Edward must still be living at that time
I looked for death for Edward and there is a death for that name but a different wife so he may have married again after death of Neva
EDWARD MILTON HAMPTON age 93
died Oct. 16, 1979 Kelowna, B.C. Canada
born Oct. 17, 1885
parents names not shown
wifeViola Ruth Brown
I went to the wills index at familysearch.org to see if I could find a will for this Edward to see if he is the right one. Sometimes I've been lucky to find a will but many times not so
I had no luck with this Edward died 1979 so looked for Neva but did not find her either.
the above from familysearch.orgwhich also has a pedigree file for a
it does not say much but does say born 1919 Canada
died 1972 Canada
That is the spelling shown but I am wondering if it is suppose to be Lyle ?
I looked for both names and found - in the same B.C death database
DAVID LYLE HAMPTON
born Aug. 15, 1918 Newdale, Manitoba
died oct. 15, 1972 Vernon, B.C. Canada
parents Milton Hampton and Viva (no maiden name shown)
This was the only child found in deaths for B.C.
I looked for Viola Ruth who is listed as Edward Milton Hampton's wife in his death and here she is - also in same B.C. death database
VIOLA RUTH HAMPTONage 91 - widow
born Sept. 5, 1891 Tantallon, Nova Scotia
died July 30, 1983 Kelowna, B.C.
father Levi Longard
so the Brown surname shown in Edward's death must have been her first married name I guess.
So next I looked for any HAMPTON people born in Manitoba crossing to US - as I have found people this way before - often people would cross the border to visit family or friends.
I think I got lucky with this database at ancestry.com
BORDER CROSSING CANADA TO US 1895-1956
SEPT. 5, 1942
ALVA MILDRED HAMPTON
born Ochre River, Manitoba
last residence, College Heights, Alberta
contact - father Edward M. Hampton, Port Kells, B.C.
she is going to Glendale Sanitarium, Glendale, California to study until may 27, 1944
she crossed again
DEC. 3, 1945
ELVA MILDRED HAMPTON
born Ochre River, manitoba
contact Father Edward M. Hampton, Port Kells, B.C.
she is shown as going to reside permanently in Delano, California
where she will be working at the Delano Hospital, Delano, CA
JULY 7, 1933
port of arrivalMetaline Falls, Washington
EDWARD MILTON HAMPTON
born Gray Co. Ontario, Canada
last permanent address - Winnipeg, Manitoba
contact Father William John Hampton, Winnipeg, MAN
destination - new location Vancouver B.C. - in transit for 2 days
it says he is accompanied by wife Genieva age 39
son David Lyle age 15
daughter Alva age 11
so at that point at least they only had one daughter and one son
Since Mildred crossed in 1945 still single would not find her in the latest 1940 US census.
and I had no luck finding amarriage for her in California - the database begins in 1949 so if she married before that she would not be in it
so next I looked for just any Alva/Elva Mildred born about 1921 Canada who might be in any record and this turned up
BORDER CROSSING CANADA TO US1895-1956
ELVA MILDRED PURBAUGH
ARRIVALAUG. 2, 1948 BLAINE, WASHINGTON
Born Sept. 9, 1921 Ochre River, Manitoba
residenceBox 455 Pixley, California
entered the US Dec. 3, 1945 under the name HAMPTON, Elva Mildred
she is listed as a housewife
** there is no contact name given
In 1993 - Elva M. Purbaugh born Sep. 9, 1921 is listed in US Public Records as living at5847 Magnolia Ave. Rialto, CA
So I looked for any other Purbaugh in California and found James L. Purbaugh also listed at the same address so likely husband for Elva.
There is a death for James L. Purbaugh born Jan 5, 1916 died Jan. 20, 1997 Rialto, San Bernadino, CA
but no death for Elva/Alva yet so I'm wondering if she either remarried or went back to Canada
I found what seems to be a son for Alva
LIONEL KIM PURBAUGH
April 7. 1951
mother's maiden name - HAMPTON
He is also listed in the US Public records database
1977/1990/1993at5850 Geremander Ave., Rialto, CA
I found James Purbaugh at find a grave
It has an obit for him which mentioned wife Elva M. and son Lionel Kim of Rialto and says he had two grandchildren, not named.
I did not find Alva/Elva listed at find a grave but it could be that she is still alive - quite possible in fact as she was born 1921 so would be 92 - lots of folks live to be 92.
If you google Lionel Kim Purbuagh he comes up as a lawyer in California
all I could find