I was unable to access HealthyArkansas.com, but would like to....could you please verify website address or get a bit more info from your RAOGK person. They may have a different database for Ark deaths than ancestry....which could be useful.

Ancestry does not index the Isabell you mentioned, but has these...in many of the Ark death records, at least as typed up and published (and ancestry lets you access scans of these) they do not include birth dates or indicate race of individual

Isabell Martin 1867 Craighead 22 Jan 1942
Isabell Martin Miller 17 Nov 1922
Isabell Cha Martin Hempstead 26 Aug 1919
Isabella Martin 1872 Crittenden 6 Feb 1946
Isabelle Martin Crittenden 12 Mar 1935
Isabelle Martin Lonoke 18 Apr 1915