"Trapped Inside A Domain"

A soul contract with a stronger creature would make the soul of the weaker creature stronger, so one could imagine how strong Ainsley's soul had become. 

First, she had a soul contract with the Godfather, and then the two sacred beasts. Not to mention, although Ainsley's other backers didn't have a soul contract with her, their influence could more or less strengthen Ainsley's soul. 

For example, Asmodeus's little avatar once blessed Ainsley, so even if only the bloodline was enhanced, but the soul must also be affected in a certain way. 

There was also the case of the blood clan and the soul contracts with so many loyal subordinates... 

These small fragments naturally formed a stronger soul for the little baby. 

If her soul was not strong, back then, when there were bullets inside her soul, she would have suffered a worse soul injury and might probably have become an idiot on the spot.