Molly's acting skills + Harmony's overall look = perfect Cecily, IMO.
Matheson wrote:We need to remember that Harmony did not get any episodes that focus on her Cecily.
"Thursday's Child" was supposed to; but even then, most of the attention was fixed on Felicity's career change and how everyone else
was affected by her illness. What about Cess herself
Matheson also wrote:If she is considered a main character (she is on almost all the promotional posters and pictures), then she should have been given just as many character development opportunities as Zachary and Gema were.
While she may've been in the promotional material, she was never featured or listed in the opening credits, like most of the rest of those portraying the Kings were.
There are at least a couple of exceptions, however, IMO: RH Thomson as Jasper and Michael Mahonen as Gus. RH was listed as a "special guest star" in every episode he was in; but I'd dare say if you asked any RTA fan, they'd consider Jasper a somewhat major character (at least a supporting one). I also think most would say Gus was a major character, too (MM was a "special guest star" in the last two seasons; but in eps he was in from Seasons 2 through 5, his name would be listed in the middle, under "With...").
On the other hand, Cess was never a major character, not even when Molly played her...and she was a part of the King family! You'd see hers and Harmony's names* only in the closing credits.
* Molly was listed in the opening credits for "Christmas in June", "Homecoming", and HCMK/An Avonlea Christmas. But in the final season, she was listed solely in the closing credits.