Jenny has a first-time client requesting an underarm wax. The first thing she should do according to draping guidelines is:

For a first-time client requesting an underarm wax, the most appropriate initial action according to draping guidelines is to ensure the client is comfortable and adequately prepared for the treatment. Asking the client to change into a gown, removing only her top, is part of the standard procedure because it allows for access to the underarm area while maintaining the client’s modesty and comfort. This step also ensures that any potential skin irritants or residue from clothing do not interfere with the waxing process.

Draping is crucial in a professional hair removal treatment as it protects the client's privacy and keeps the treatment area hygienic. By facilitating this process effectively, the therapist demonstrates professionalism and attentiveness to the client's needs. Ensuring the client is sufficiently covered, except for the area to be treated, is instrumental in providing a positive and comfortable experience.