Pheobe Dorin was a recast Penny.
She came on in 70 or 71 when Irna was absent. She never had any story but maybe this was intentional as they were trying to ease her in. Rosemary was so beloved that I'm sure there was negative response .'That's not Penny!!'
Pheobe was dropped after a few months.
Let's just hope it was a case of bad luck then I tried too but I'm usually jinxed, and the fact that not knowing when exactly Jane played the role doesn't help much, I found the Carmen Duncan episodes so much more easily
I imagine that that credit was wrong because I hunted the episode down and she wasn't there, I don't think Rosemary would willingly only make one appearance unless it was really special
I don't doubt it, Rosemary had that interview in that she said the public would not accept another Penny and she was soon let go