Not too much really, since Estella rotates party members pretty often.

I'd mostly say her team choices often indicate a preference for battle prowess. She doesn't really keep any unevolved Pokemon around nor does she show much interest in catching "weak" Pokemon. If Estella's catching an Eevee, that Eevee needs to have an interest in evolving and battling, or she'd release it back into the wild.

She caught a Wimpod because she knew it'd evolve into Golisopod. While she did treat Ares quite well as a Wimpod, she probably would have passed on him if she didn't know about his evolution, and she would have released him if he'd had no desire to grow stronger.