Andrew,
It looks like Evaline had separated from her husband/moved in with her daughter (Effie) prior to the 1920 US Census and was living in Massachusetts. Sometime after that census, they all moved to Texas. If she had been living there for 3 1/2 years prior to her death, that would put it at about 1821. Since it was only a few months after the death of her husband, perhaps that could be used as a reason for the suicide (if it was a suicide and not an accident). That's just my best guess as I couldn't find anything else documentation-wise.
Hope this helps,
Ken