Hello again john,
I am only a tax consultant with this website, and that is where my area of expertise ends.
The Just Answer website is broken down in to different categories of experts, such as legal, tax, financial, medical
questions, car questions, etc. There is no one particular area that I know of on this website that deals with help in locating people, so I am not sure there is really even anyone on this website that I can refer you to for help.
It seems to me on the surface that you at least have some substantial starting information, so possibly someone from our UK Law team would have some suggestions for you. You can post a new question in that category, and of course if you do not get a satisfactory answer, you do not have to Accept the answer, and would therefore not be charged. So that is where I would suggest you start.
Good luck john, in locating this girl's father.