I checked the estate case file index at the Alabama Genealogical Society website and no entry found for an Alexander Jenkins having an estate case file in Henry County.

http://lrp.algensoc.org/lrpw/loader2.html

Now it is possible that there could be a record in the Orphan's Court record book for him. These books have been microfilmed.
Henry County AL Orphans records v. C-D FHL film # 1288511 These two volumes cover 1822-1848.