Another article from the times
under wills and bequests may 21 1958
WILLS AND BEQUESTS LIEUTENANT-COLONEL MERVYN JOSEPH PIus O'GORMAN, of Embankment Gardens, S.W., consulting engineer, left ?163,224 gross, ?161.654 net (duty paid, ?86,872). He left ?3,000 to the Royal Aeronautical Society; ?2,000 each to the Athenaeum Club, the Royal Institution of Great Britain the Institution of Civil Engineers, and the Institution of Electrical Engineers, ?1,000 to the Institution of Mechanical Engineers, and ?500 to the Art Workers' Guild
No mention of a daughter. To be honest the evidence that he had a child is slim yet the preponderance evidence against him having a child appears stronger.
II did consider that the model might be someone who was payed to do pictures etc, but I'm starting to go against this idea due to the fact that she is seen sitting next to 2 other young girls. Unlikely he hired three girls and only did pictures for one. I also doubt that the pictures were all done on the same day.
the other interesting factor is that Mervyn was from a Celtic bloodline and the girl looks likely she is from ta Celtic blood line i.e red hair. As Ive said before she looks like the spitting image of my first wife who was also from a Celtic blood line.
None of this on its own is proof but does push to me believing this girl is a related to Mervyn.