Thanks again for your thoughts Grinity.
In my elder DDs case it is becoming clear that she is profoundly visual-spatial with some sort of auditory and/or visual deficit. When she was assessed by the OT at 7.5 yrs with less pre-reading skills than DD2 has now at 4.5 (and has had for a year or more) he actually said "I can see from her visual tests that she is great at "Where's Wally" but can't read". For whatever reason she never noticed the words on the pages of her books until they were painstakingly pointed out, or the symbols for numbers. So in her case there is some manner of LD at play. Given she's bright bordering on gifted, a perfectionist and very strong willed, teaching her to map words (or numbers) to symbols was agonising for everyone.
"Teaching" DD2 to read on the other hand is a breeze, it's just curious that she hasn't self started more given that she insisted on playing starfall until she knew the alphabet completely before she was 2. She loves to play word/sound games and has a great sense of rhyme. Her pre-reading skills are all there, and have been there for literally years. But she hasn't tipped over into reading on her own. We haven't had time to help (pregnancy from hell with DD3, followed by DD3 screaming for most of her first year while we were trying to deal with DD1s delays at school - poor DD2 is suffering from ultimate middle child syndrome!), also she has seemed more interested in writing than reading.
Although now that I say that about being more interested in writing it makes sense. She's always been more interested in her own ideas, opinions, stories etc than other peoples. That sounds terrible and I don't mean it to be, she loves people and is a very friendly and generous soul, but it makes sense that she would be more motivated by getting what is inside her OUT than by getting what is in books INTO her, if that makes sense. And there is nothing like a perfectionist older sister telling a perfectionist little sister they aren't doing it right to squash a budding writer :-).
