Dialogue is a bit clunky here..
"I was convinced it wouldn't work.." doesn't have much of a lead in from him asking if she was crying. She should of stated her aw of it working first and fore most - then got choked up, would've made a more emotional impact.
Though, why Rachael is getting so emotional after figuring something out is a bit odd, it's not the first time she succeeded at a task on the farm. Wouldn't her being useful or finding her place be a more emotional reaction?
Also she was said to be a prodigy in her origin comic, so we assume as a kid it meant she was highly skilled already - spending her life on the streets, being a dedicated fighter -ect, it's not like we've seen Rachael *lose* much in the course of the comic, on the contrary - she has gotten almost nothing but windfalls save for the Minos kiss, Fight with Mora and being pared with Miles..
Also it weirdly gives Miles a backhanded compliment.
Anyways, I wonder how long until we get a sex scene between these two to top off the comic.