I would say that you should not judge the egg quality until she has produced at least 20 eggs, though it does sound like she may be some sort of cross or poor quality genetics.
Often people think it is best to buy unrelated males, and this should give increased fertility, hatchability and all round vigour, but it is a scattergun approach at best. They have discovered at least 13 genes which are responsible for the dark brown shell colour, so when you have 13 from the female and 13 from the unrelated male that does make for a huge number of potential combinations.
If you have a flock of female producing indifferent colour tinted eggs and you use a male from a good dark line then there will be a vast improvement in shell colour, but when you already have dark egg laying females it becomes that much more tricky to hold, let alone improve the colour.[size=78%] [/size]
And if she didnt come into lay until 40 weeks old then obviously only to be kept as a pet and same would go for her brothers. Certainly not worth keeping and breeding from - though all the info about what causes egg colour would still apply.
I would expect any laying bird to come into lay at around 24 - 28 weeks and anything much over 30 weeks would send the signal as a poor layer that should be discarded from the breeding pen.