I can't remember it well, maybe someone else can, but there was something about Hannah's looks that was a reason why Kate had her hair grown longer than the others. I can't remember what it was, but someone once posted something they had found about it.
You thought she was doing a lot of whining last night? I saw it as just a show of someone with a zillion kids going school shopping (yuck). If TLC didn't need to tape it, I think it would have been much easier to take the twins one night, the little girls another and the little boys another. I couldn't have survived taking them all, and listening to all those kids whine at the same time LOL.
I have no idea why she singles Hannah out as her favorite but it seems very unfair, she has 7 other children afterall, she reminds us of that fact every 3 minutes

As for the episode last night, yes I did think she whined quite a bit. She should move forward and show that she is capable of getting the things done for her family without all the drama and excessive complaining.