Auntie Clara Wakefield is somewhere between 50 & 70 and constantly trolling everyone. She attends Church every Sunday but outside of those two hours a week shows no indication of believing in anything, certainly not what the Church teaches. She has a fraught relationship with her family but is still in contact with them occasionally.

The first foundling was her brother's bastard and she got a bit of hush-money from him and his wife to make up a believable back-story for the kid, but she picked the Vice name because she was legitimately super bitter about this and mostly agreed due to pressure from her parents (of the well your life is already basically nothing, it would be selfish of you not to do this to protect your brother's reputation and career sort).

The second one she took in because she kinda liked having a kid around she knew it would antagonize her family but lol what are they gonna do about it.

The third was probably related to her in some way (either another bastard of a more distant relative or a friend of the family or something).

Fourth onward could have come from anywhere because at that point why wouldn't people just drop them off at her door? No material difference between six and seven foundlings... :P