Yet was a model, embarked on a modelling assignment to Japan, (solo travel) had a social life, went on a few dates with men, was a regular on the London club scene,
Stop making Shelia out to be zombie from people whose recollections are detrimental to Bamber due to personal dislike and monetary reasons, and furthermore are tainted by the wisdom of the event
I think that should read "Had once tried her hand at modelling". Her parents paid for her to do a course in which a photo shoot/assignment was included. Had she had what it takes to be as model, more work would have followed. It appears such was not the case. In fact, if we look more deeply into Sheila's accomplishments, there were very few, if any, save for the major one when she produced the twins, albeit, not without an enormous amount of input from the medical profession.
You and Adam have polarized views of who and what Sheila was. Neither of you are entirely wrong, but nor are either of you entirely right.