The sister does not look like that AT ALL. In fact, until about 6 weeks ago, I couldn't tell Doris and Barbara apart. The blue mottling just showed up around the middle of August out of nowhere! None of Linda's chickens look like this, either. She's the only one with the blue mottling.
There must be a recessive gene or something, but everyone that comes over says she's the most strikingly beautiful of all the birds in my flock.
And both of the BWA girls are very sweet and will readily sit on our shoulders and peck through our hair to see if we have piojos.
ETA: My landlady is going to let me use her digital camera later to get clearer pics, and I'll post them either this evening or tomorrow morning.