Benjamin Hallack's will was probated in 1823 at Image 50-51 of Bourbon Co, KY Will Book G on familysearch.org. Note the images contain two pages for each image. His will starts on right hand side of Image 50 and covers both pages on Image 51.
https://familysearch.org/pal:/MM9.3.1/TH-1951-20785-52143-83...The pdf document I referred to earlier is an abstract of this will by an unknown author, and continues with real estate deeds over the next 20 years involving transferring property back and forth between siblings & in-laws.
For example, you will see that the property that Jacoby received in Benjamin's will (or just her dower interest) was sold to Rachel (Hallack) Thurston's husband by his widow, Lucinda Hallack on 6 Jan 1842. So, he had apparently died by then? If he hadn't died Lucinda would not have a dower interest, I believe.