Adam was glad after hearing about her past which not only proved to him that she was more capable and worthy of working with him, but also revealed to him her reason for wanting to succeed.
With such a big weight that she was carrying from her ancestors, Elizabeth had great ambition and drive and was exactly what Adam needed from a partner.
It also showed him that the world wasn't as big as it seemed and he was lucky to have made his first step into the underground world of cultivation with a steady foundation and partner.
He was also beginning to realise that New York wasn't as big as it seemed and the large families of new york that each governed one borough would have spread to the rest of the country and the world if there wasn't something stopping them. Which showed him that they weren't the only cultivation families he had to be wary of and there were stronger and more influential cultivators out there in the world.