o, I don't believe that Mahaley was the daughter of Jacob and Susannah Ahart.

It is far more likely that she was Jessie Mahalia Ahart, daughter of Adam Ahart and Mary Elizabeth Tune. She does not show up in the 1850 census to prove it, but then the census taker evidently made some errors in his enumeration. He lists two children named Jacob a year apart.

The earliest census I find Mahala named in would be the 1870 Auglaize, Camden, Missouri census. She states there that she was born in Tennessee in 1841. It's possible that Jacob was still in Tennessee at that time.

Look further and we see that all of the children listed in the 1870 census for her were also born in Tennessee. This means she arrived in Missouri about 1869-1870.
Jacob was in Trigg Co Ky by 1850, when Mahala was a mere 9 year old girl. I would think she would be in the same state with her parents at that age.

Adam Ahart, who I believe to be Mahala's father, died in 1870 in Cole, Missouri