Trying to find sister

My half sister, brother and I are all trying to find our sister. She was born on September 26, 1987 in Woonsocket (maybe Providence), Rhode Island. Her birth name was Kelly Schobel. The people that adopted her did not want to keep in touch with us. We've been hoping that she's been trying to find us since she turned 18. But we don't even know if she knows she was adopted or if she's even still in Rhode Island.