This is very random.
It seems to be universally accepted that Inezh is actually Una Kavanagh. The two look identical and every article I've read points to her, except the part where she denies it.
The thing about that is people lie, especially if they are embarrassed or ashamed of something. Perhaps since she was so young and inexperienced in the performance she isn't proud of it, or maybe she is just tired of being asked.
My brother and I are very close in age, in fact we are the same age 3.5 months of the year. We always used to be asked if we were twins and for a long time we would say no and explain, but after a while it just got easier to say, yes we are twins. This is obviously not the same but it proves my point. Sometimes it's just easier to change your answer.
And last but not least, if Inezh isn't Una, then the topic should probably be left alone, as anyone who wanted credit for the roll would have taken credit. The actress probably doesn't want the publicity that would come from admitting she played one of the most popular characters in a very successful survival horror franchise. Privacy is priceless and she deserves to have it if she wants it.
We mustn't find her. If she wants to be known she will make herself known.