Meryl is a very minor character, for now. She's all business and to the point but really takes joy in figuring things out and out-thinking others. Her voice is reflective of this by sounding like an inquisitive, young business woman. Don't play up the age with this one. Go for young but mostly serious. Think someone like Penny from Inspector Gadget, if she were in her early 20s. She also has a fun side that comes out when she figures things out. She has a sense of pride in her work and in her abilities which makes her a bit cocky. Almost the female Sherlock Holmes of the series, in terms of personality, but less socially awkward.