Some thoughts for you~

Karen Calloway - I suspect she and Arabella could be mischief friends. Like "leave the baby with my butler and let's go check in on someone" sort of thing. Also there could be some friction if Arabella decides to grumble about "no good snake oil salesmen"

Uriel Meijer - These two could also be friends, though she'd probably try to convince him science is better than history or tries to get him interested in paleontology because that’s like history, right?