Hi Phil,
I searched Ancestry and FamilySearch and found the following:

In 1860 a Carmel Richards and family were living in Pajaro, Santa Cruz, California.
Charles Richards, b. NY, 44, farmer.
Carmel, b. CA, 30.
Maria, b. CA, 4.
Robert, b. CA, 1.
David, b. CA, 1/12th.

In 1870 the family was living in Monterey, Monterey, California.
Charles J. Richards, b. NY, 57, brick mason.
Carmen, b. lower CA [Mexico?], 40.
Mary, b. CA, 14.
Robert, b. CA, 12.
David, b. CA, 10.
Julia, b. CA, 8.
Adeline, b. CA, 3.
Harry, b. CA, 2.

In 1880 Carmel and family are living in Castroville, Monterey, CA.
Carmel Richards, b. Mexico, 49, head household, housekeeper.
Robert, b. CA, 21, printer.
Julia, b. CA, 18 seamstress.
Addie, b. CA, 13.
Harry, b. CA, 12.
Josefa Ypolito, mother, b. Mexico, 75, no occupation.

In 1900, A Mrs. C. Richards was living in San Jose, Santa Clara, CA.
Mrs. C. Richards, head, b. Mexico, March 1840, immigrated 1850, no occupation.
Addie, b. CA Sept 1870, single, dau, dressmaker.
Josie Ward [however the spelling on the Census is mangled, might not be her name], b. CA, March 1882, neice, single.

I didn't find Carmen's death info.

In 1910, George and Adeline McMahon and Richards were living in San Francisco Assembly Dist. 35, San Francisco, CA.
George T. McMahon, b. MA, 58, M2=2 yrs, salesman.
Adeline M., wife, b. CA, 39, M1=2 yrs, father born=Canada English & mother born=Mexico.
Harry T. Richards, brotherlaw, divorced, b. CA, miner, 41.
Eugene R., nephew, b. CA, 14.
Carmen, neice, b. CA, 13.
Dorothy, neice, b. CA, 10.

I think Adeline and Harry are brother and sister. It says that ADeline's father was born in Canada=English. I've seen other situations where the Census said someone was born in NY and actually they were born in Canada.

A Harry T. Richards, native and loyal citizen of the U.S.
Born: June 19, 1868, Monterey
Father born: Kingston, Canada
My father has been dead a long time and I have no knowledge of where his naturalization papers are though he told me many times before his death that he was naturalized.
Residence: Duquesne, Arizona
Occupation: miner
Wish to go to Mexico to examine some mining claims near Torres, Sononora in which friends of mine are interested with the purpose with the purpose of acquiring an interest therein, if found satisfactory after my examination by me. It may also be necessary for me to go to Lower California for the same purpose-in the northern pare thereof.
Sworn: 10 May 1919
Harry T. Richards
Passport Issued: 24 March 1919
Source: U.S. Passport Application, 1795-1925. NARA microfilm Publication M1371, rolls 1-2.

In 1930 Harry T. Richards and family were living in Nogales, Santa Cruz, Arizona.
Harry T. Richards, b. CA, 62, both parent's born England.
Julia, wife, b. Mexico, 34.
Woodrow, b. AZ, 12.
Doris, b. AZ, 8.
Henry, b. AZ, 5.
Robert, b. AZ, 3 6/12ths.

I didn't find Harry's death information.

I didn't find anything on Jesusa Simbreros de Stevinson.
At least the above provides more places for you to investigate. Successful Searching!