The Lost Child: A Victorian Romance - Westminster Orphans, #3

Separated from her family Abandoned by her adoptive parentsStolen by those that prey on children. can Tish survive?  At the age of 5, after the death of her parents, it seems at first that Letitia Shaw is the lucky one. Adopted by her father's wealthy business partner when the rest of her family are made homeless and consigned to the slums of Westminster, Tish lives in a beautiful home and wants for nothing.  But Tish knows that the Thompsons don't really care for her, and yearns for her lost family.
Her only confidante is her new cousin, Archie, who is a constant thorn in his parents' side. The two of them become fast friends over the years. and then disaster strikes, and the cousins can rely only on each other to survive whatever life might throw at them.  Unused to the darker underbelly of London, Tish and Archie immediately find themselves ill-equipped to cope. All too quickly, Tish is caught up in a far more precarious situation than if she had been taken to the workhouse.  After Tish disappears, Archie vows to find the little girl he vowed to take care of.
but London is a big place, and Tish is well-hidden.