I have no experience with this Plush, but I think you can analogize to hiring a stylist or make-up artist (or accountant, or lawyer, or any other personal service purveyor)
First, you'll need to do a little back up research. Is this a person with a background in the industry--in some way--or is this just someone who likes clothes and dressing people, but has little to no experience otherwise? Get references if you can. How have other people liked her?
Second, do you like the way the person looks? The ultimate warning sign for me whenever I am looking for advice on make-up or hair is whether I like the make-up and/or hair of the stylist/adviser. I do not even ask for help from someone who has bright blue eye shadow, caked on mascara, tons of blush, and a facial skin color 5 shades darker than her neck. I like natural, and that person probably would not quite understand "natural." (And this is also from experience, where the interpretation of "natural" varied greatly between me and her). So for a shopper, do you like how she carries herself and her sense of style? It might not be yours (i.e. you might be boho, she might be urban) but do you like her style?
Finally, you need to meet with her. Do you get along? Does she respect your own style and your own personality, or will she impose her own ideas of right and wrong on you? If you do not feel comfortable with her, do not waste your money.
Just my two cents.
