My Secret Princess

in this story rose is a secret princess with her sisters
their kingdom vanished because of the 6 years ago
war.Their parents died.In order to live.A woman in 30's save them and helping them by growing up but one day the woman got sick but she cannot die she needs to be replace the princessess agree to it..

what could happen??
will she found their true love??

ROSEKOOK STORY but maybe i'll include
Jinsoo,Namjen,Lismin