Firstly it sounds like you are naming them after the royal family, which tickled me in all the right places! Camilla does totally look like a Speckled Sussex, and does kinda look like a boy (MPC sent me a boy SS on accident too!). More importantly, maybe Camilla is just behind because of the delay caused by being small, getting a rougher start. I wish I had more to say in terms of knowledge, but it sounds like you are doing all the right things. If I were in your position I would be giving chick vitamins on occasion, some yogurt for probiotics from time to time and just good feed (and asking questions on here!). I hope he/she catches up...and doesn't become a "he" like the comb and wattles predict right now, it's a bit early for the pink wattles and that comb looks like it has popped a bit for this age to be a pullet, but it may stop or slow in the weeks to come, it's really early to tell. Good luck!