What’s the name of this movie?

I watched this movie abt 10 years ago when i was small. I can only remember the beginning and the end of the movie.sorry for less info… please help me figure out the name….i want to watch in again!!!

beginning –
there r 2 sisters…one abt 7-10 yrs…other abt 13-15 yrs old ….they were in a garden with their mother….their mom was on a swing…a rope swing with flowers …..those girls r also playing nearby…..suddenly they hear a noice….a sobbing voice….they both go n see…..they found a cave….big stony cave…..there’s another girl abt 12 yrs…facing the stone….covering her face with hands..(like when doing hide & seek)…sobbing…she had beautiful hair too….those two sisters go closer….the little girl steps more closer to the crying girl….but the elder sis says lil sis to stay closer to her…the crying girl is few steps away from the two sisters…..these two sisters have a power…when they clasp their hands together, no one can hurt them…..so the big sis clasped hands with the lil sis and asked her not to get closer to that crying strange girl……they ask that crying girl why she’s crying…..then she turn her face to them …..its not a girl…it’s a monster…….he evilly laugh….little sister get scared n tries to run, but big sister says something like – we r safe till we dont let each other go …..but the lil sis was too scared , she let go of the hand and runs back to their mom and tell her a monster got their sister….but at the same time big sister comes and tell she’s fine…but the movie shows us a tattoo like symbol behind the big sister’s neck (i cant specifically remember the symbol the tattoo had) , which means the monster actually got her (possessing her )

the middle – they r big now, big sister has become evil and left or something….lil sis is searching for her big sis with her friends ( i cant remember the middle part much)

the ending scene –
big sis is now evil n she lives in a castle … little sis finds her evil sister and at the end they fight … on a balcony … i think the little sis tries to make her big sister remember their past and how they used to love each other…but the monster inside the big sister doesn’t allow it…but at last little sister manages to clasp her big sister’s hand… and their power rise….so the evil monster leaves big sister’s body, and the real sister remains…she then remembers everything…how much she loved her sister….the end

this is the story…..pleaaaase help me find the name