My ex-wife was adopted from Dr Banardos when she was a baby.
She never knew who her biological parents were until about 6/7 years ago when her step-dad received a letter from Dr/B asking him to ask his adopted daughter (then 52) if she would like to meet her real mother as she had not long to live.
She had made a confession to her other two daughters whilst in hospital that she had another daughter from a fling she had with a Frenchman, and it was her daughters who had made contact with Dr/B.
By the time this process went through her mother had died but she agreed to meet her half sisters as she wanted to find out how she had died and what if any other medical hereditary problems she may have had.
They don't keep in touch as she told me that they had nothing in common and as far as she was concerned her adopted mother and father were her real parents who she adored who unfortunately have passed away, but she goes regular to there resting places to lay flowers and say a few words.