I posted a message on the following website, on behalf of a very close female relative of mine:
http://www.ukpeoplefinder.com/
This message eventually lead to Mum & her adopted son being happily reunited in 2004, after 39 years.
I wish your daughter every success with her search & admire you so much for assisting her.
The reason I mention this, is because in our case, the adoptive Mum of the young man, forbade him ever to try to make contact with his birth Mother. This led him to do so behind her back & she died in October 2006, never knowing that not only had he found his birth Mum, an older brother & extended family, but that he was so very, very happy.
He truly loved his adoptive Mum & it broke his heart not to be able to talk to her about finding his birth Mum - but that was her decision & would never waiver.