SOLVED. Middle grade, read in 2017?~ Orphan girl is given jewels by a dying woman.

[Aishwarya]

An orphan is hired to look after an old, sick lady. The lady gives a pile of fake jewels before she dies.

Later in the book, it is revealed that the old lady tried to sell her jewels because she didn't have money, and the pawnshop owner loved her, so he gave her the real jewels and money, but lied and said the jewels were a fake copy for her to keep.

Another lady tells the orphan she's her mother just to get the jewels. There is a scene where the orphan girl is leaving on a boat to go to her 'mother', when her friends call out that she isn't her mother, and the girl jumps off the boat.

[Aishwarya]

I figured it out: It is called the Star of Kazan by Eva Ibbotson.

[Rainbowheart]

Glad you found it!

The Star of Kazan for the link.