I've looked for Lulu's death info in Ancestry, FamilySearch, Archives, findagrave.com and newmexicoalhn.net but can't find it. I wonder if she married after being married to Mr. Underwood.
There is a look-up volunteer at sandoval.nmgenweb.us/resources/lookups.html who might be able to help.
I checked Western States Marriages but didn't find her listed there.
The New Mexico Genealogical Society, nmgs.org/church-Sando-html might have the copy of the newsletter that you're looking for. However, indexes of the cemeteries can be found at newmexico.coalhn.net.
You might want to check with the Sandoval County New mexico Genealogical Society, scnmgs.weebly.com. Maybe they have obituaries.
I did find Ira Underwood Born: 22 April 1895 Last Residence MAYBE: San Ysidro, Sandoval, New Mexico Died: Jan 1978 Last Benefit: Albuquerque, Bernallilo, NM His soc. sec. # was issued in New Mexico in 1953. Source: Social Security Death Index
I marked his Last REsidence as Maybe because Social Secuirty uses that field for other purposes, therefore, it might not be where he was last living. Successful Searching!