Susan is doing her best to not let her frustration with the situation show (too much). She has a hard time imagining how any woman could be satisfied with what there is on display. Everything is either too pale or too bright. She'd become accustomed to rich jewel tones, fine fabrics, the sorts of dresses which impressed.

She imagines that some of those who'd sought her hand wouldn't mind seeing her in some of the dresses. That makes her even more determined to maintain her dignity.

And she gives Lucy a questioning, almost-resigned look. "Trousers. Trousers would at least come to our feet."

(she has no idea what "Juicy" means in context and strongly feels that she doesn't want to know)

But there's a salesgirl. Susan smiled, prepared to use charm to get what they needed. "Yes, pardon me. But can you direct my sister and I to the seamstress. I'm afraid there must have been some mistake!" And she added a chuckle, trying to draw the salesgirl into confidence.