Long history here: Nathaniel Nelson Graves Allen left his first wife Celia Bloodworth and set out for Texas in 1826. As far as anyone can knows or can find, there was no divorce from her; he abandoned her.
NNG was a Methodist minister circuit rider, so he traveled all the time. They moved quite a few times, and perhaps Celia thought the move to Alabama would be their last. It would not have unusual for NNG to go to Texas on his circuit.
They had children born from 1791 to 1819. The older ones were grown by 1826.
NNG married Margaret Quinn in Texas. He named his children in the second family after his siblings, perhaps so relatives would know this was his family or because he missed the family he left behind.
There's quite a bit more on this family. Peg Spencer