Regency Romance - Woman runs a safe house for women/kids in need

I read it a few years ago and can't for the life of me figure out what book this was.

The heroine has a drunk gambler father who has often 'lost' her in a game of cards. She runs a safe house for women and kids in need and a lot of the servants are women disguised as men. There's one scene where the heroine and a few friends are tarring the roof of the house.

The hero is 'hired' by his friend (may be a duke) to help locate the duke's(?) younger sister that ran away. The sister is pregnant, but the older brother doesn't know that. The trail leads the hero to the heroin and her house. The heroine helps keep the sister hidden from the hero. The brother is so straight laced, the sister was afraid to tell him about her situation.

The brother eventually finds his sister and they have a wonderful reunion. The straight laced brother gets his own book next. I think this book is the second in the series. If I'm not mistaken, we are introduced to the sister (either by the character's entrance or the story of the scandal) in the first book. The second book is her hiding out. The third book is the straight laced brother's book.

I think this might be the Brothers Sinister series by Courtney Milan. First book is The Duchess War.

>2 leennnadine: No, I thought that, too at first, but I recently reread them and they weren't it.