"We're looking for someone with a wide vocal range"
You don't need a "wide" vocal range to be an excellent singer. Julie Andrews' vocal range spanned 2 octaves and 2 notes. Judy Garland spanned 2 octaves and 3 notes. Both are considered some of the best female vocalists that ever walked the planet.
Not to mention, a wide vocal range is the least important component in a singing voice. I'd worry more about understandable diction, proper breath support, good vibrato, vocal strength, being able to hit correct notes, and being able to emote.