Thanks for your reply Erin. I'm glad I was on the right track. A couple extra days has confirmed the oldest chick is definitely a female -YF II sky blue opaline, I think second chick a normal cobalt blue, 3rd chick up in the air but has white down so maybe another opaline?. Don't know if I'm imagining the plum eyes or not.
As for mum, she is the same age as Dad - 12 months old, she does look younger than him doesn't she, but I've had her 12 month now, since she was a fledgling. She has had dark eyes all along. I know she is still young for breeding, but I'm afraid initially it was unintentional.
She started laying very determinedly at 9 months, and when I didn't give her a nest box she laid eggs on the floor of the cage and attempted to sit on them. I had planned merely on pet budgies, and naively didn't realise that in a house cage inside - in my kitchen no less and with no nesting box, they would still breed!!! I know, newbie. Anyhow, needless to say first batch was not successful ( I hadn't been feeding anything but seed and she had no box) and although she hatched one chick, she was too inexperienced to feed it, as was I! So this time round I recognised the nesting signs in advance (duh! shredded newspaper flying everywhere) and decided to let her have a proper go. Dad also being inexperienced has not been feeding Olive (mum) so I have been giving her fresh egg and biscuit twice a day inside the nest box to keep up her condition and assist her with feeding the chicks. She has been a very good mum this time round, and the 3 chicks are growing well. So all in all it hasn't been ideal circumstances, and I do plan to separate them in future, as I have no idea of their lineage and they may even be related, as they came from the same outdoor aviary and are the same age