No you are not. Macro lenses of DSLx style cameras are used for stuff like "picture of a housefly" or similar stuff. Specialist lenses that are not needed for model fotografie. The classic "kit" lense like the 18-55 is normally "good enough" for model pictures since you are using rather large f-stops (f/8-f/16 depending on sensor and lens quality) for maximum depth of field anyway. And the minimum distance of some zooms is not that much bigger anyway. I.e my Tamron 24-70 is "38cm" and a Tamron 90/f2.8 (a full featured macro lense) is "30cm".
Since some macro lenses (i.e the Tamron 90/f2. are also quite nice portrait lenses some fotographers that prefer primes have them anyway and then use them.