Rescuing people

Abigail Chantry is down on her luck, working as a governess she has to deal with the issue of being neither servant nor family. Working in a household where the family treat her negligently and when she explains that her sister is suddenly in town and needs shelter they refuse her permission. However her sister has been sold to a brothel and now needs to be rescued, along with a maid and another kidnapped girl.
So they end up out on the street and in desparation Abigail breaks into a house to see if there's anything she can steal and instead finds a very neglected woman, Lady Beatrice. Her sense of justice is such that she goes to Lady Beatrice's rescue, ridding her of staff that are exploiting her. When her nephew arrives in London to find cousins he knows he never had sparks begin to fly.
This feels like a story I've read before, but it was very enjoyable and a great story of found family. I'm glad to see it's part of a series, I want to see what happens to the other girls.