The first is standing outside the Science Lab Tower in the northeast part of New Ark City.
The second can be found in Transylvania, just before the gates to the Graveyard. She'll only be there after you've rescued everyone from the Manor.
The third is in the Slums area at the Devil's Drink after you buy everything from her sleep and she should be at the Gentleman's Club where you need to buy everything she sells again and sleep then she will be at the top area of the slums where you enter and you will need to once again buy her stock. As for bell, you can gift her a cow bell collar to keep her from running away.