She begins to look for that shifter right away. It is a pretty difficult mission but nothing she can't achieve.
She lands in Heinhoss where it is a lot more likely to find Shifters. She enters an office at night where she looks among several birth certificates; no luck, as it is not specified.
Her next move is finding orphanages, so she proceeds that way.
She manages to find shifters' community after a lot of searching. She secretly looks into some interesting background that could lead exactly to what she is looking for.
Eventually she manages to get to the right one and organizes a plan to capture him.

A simple Palace maid, moved there because she had nowhere else to go. At least the Palace could bring both shelter and occupation so she went for it and she was assigned to the princes just recently.
Saving the princes and bringing them to safety definitely makes her earn some respect from the Empress. She is just a young girl with no background after all, not even any family or place.
Her skills get tested and she ends up defeating the best palace guards, not always fairly, but it is still win. She gets promoted and now she will have to follow the princes full time. She actually expected a big reward from it, but that is also fine to her.
They move the princes on a ship. She is given a high rank there.
It is evening and the sea is very calm. She is wandering outside.

She is a Shinobi.

She is 16 years old.

She has a twin.

Her original name was Haru but she had to change it and chose Miku.