Sister born 11/26/1950 Sidney MT

I am looking for my sister born in Sidney Montana on 11/26/1950. I posted on my first adoption web site in 2000, so it has been 16 years of searching. The hospital records show that she was discharged on December 2, 1950, but no information as to who she was discharged to. Vital records in Helena MT has an adoption file for a baby girl born on 11/26/1950, but not under moms name or maiden name.I have spent hundreds of dollars joining groups and hiring a confidential intermediary. The CI hasn't found anything and won't share what he says he found. Wasted money on that...Any help at this point is appreciated.I have done a DNA test and am on 3 Facebook pages, and several web sites.