This book was a fun romp. I adored how much attention Annis paid to fabrics and fashion through out all of it, even though she's starting from a very small skill-set as an actual dressmaker.
Unlike many books with *surprise* secret spy family members, Annis does not strain my suspension of disbelief. She starts out the book as a fairly sheltered, normal, naive, fashion-obsessed young woman of her time, if a charming one with a kind heart. The sense of the world spinning on and on outside of Annis' sphere is one that I love. Her growth over the book is lovely to follow, and her unexpectedly useful talents are all things that she regards as extremely normal. (If *you* had her Aunt Cassia, you'd know how to do basic ciphers, of course!) She's resourceful, charming, brave, kind, and EARNEST. I *love* an earnest heroine.
Millie could be the heroine of her very own story, and the best part is that this story totally acknoledges that. I love it. Just because Annis is the viewpoint of this story, doesn't mean that Millie is less of her own heroine. Same with Aunt Cassia, Miss Spencer, and others. On a meta level, the way that Jones pulled in characters from other worlds and novels also plays to this theme -- everyone is the hero of their own story, with their own rich inner life etc. It's even lampshade with Miss Smith, commenting that Annis was an entirely inappropriate choice for a spy as she would always be the center of the story, never able to be on the edges like a spy must.
Anyway, back to Millie. I felt like the book did a good job of handling the class and employment balance of power stuff, as well as building the friendship between Millie and Annis. I look forward to seeing Millie develop into a powerhouse of her very own.
There's a fairly tepid romance through line with Mr. Harrison, which was limp in a way that made it a little odd how much the book kept drawing the reader's attention back to it. The much more engaging romance through line was between Miss Spencer and Aunt Cassia -- I was to see *that* one explored more.
This is totally a YA book, but it's not one that seems to think younger readers need to be talked down to. The POV character is a teen and FEELS like a teen, but the problems she deals with -- her friend/employee's continued sexual harassment by a local big deal, her parents' deaths, being broke, etc -- are all Big Deals. IDK, I enjoyed it.
TL;DR -- fun, fluffy romp. Strong rec as a beach or light read. Will be looking forward to the sequel.