A great story! I love the twist, and that Charlotte was able to name one of her daughters for Lizzy (one wonders if she has another named for Lady Catherine!). I also loved the ambiguous language - Mr Darcy and his cousin, who of course is also a Mr Bingley, was a particularly nice touch.
One tiny nitpick is that blueberries aren't native to the UK, so Elizabeth wouldn't be picking them. Depending on the time of year, strawberries, raspberries, blackberries or currants would be more likely. (Although the idea of her picking sloes for slow gin is amusing!) It bears no bearing on the story whatsoever, just a tiny Brit-pick.
I look forward to your next offering!