OP has a point. Here's a lesson for the writers out there: often, you can develop a character without even changing how she acts or thinks. All you need to do is put her in a new situation where, though she acts the same, the audience will interpret her differently. Dash didn't do anything in this episode that we haven't seen her do before,but because she did those things while standing next to another, similar character, she now comes off differently to the audience. Character development = achieved.

Nicely said, OP! but she is still far from perfect, and she is actually more aggressive than ever.