Kim Smith was born in 1983, and appeared in Maxim in 2000, putting her at age 17, not friggin' 13 at that time.
I felt confident the OP was wrong in his memory of "13" so I went and looked this stuff up.
Another important point is that as you can see on the cover, she was VERY developed at that time. Nobody who had a weird, unhealthy attraction to children would perceive her as such, or gravitate toward that imagery.
Also keep in mind, there are plenty of places throughout or world where 17 year olds are still considered adults, or even 16 year olds or even younger than that in some places. Aren't there still some southern states where you can get married at 15 and crazy stuff like that?
I'm not endorsing any of those laws, just pointing out that the magical number of 18 isn't chiseled in stone within the halls of mother nature, or anything like that. Throughout 99.99% of human history people tended to have some very different notions about consent, age of maturity, appropriate age to marry and have children, etc etc. Ideas which, quite frankly, matched up with biological reality much better than our own.
They were dealing with different considerations though about life expectancy, infant mortality, and many cultural issues which we are largely free of in the developed world now. I largely endorse the attitudes we have toward these issues now in the USA. THOUGH THEY ARE NOT PERFECT.
When I hear stories about 18 year old boys going to prison and being registered sex offenders for life because they slept with their 17 year old girlfriend... I and anyone else who hears that should immediately know our system isn't perfect. At some point though the system had to make a decision about a certain age and stick with it. It's not practical to have the government issuing maturity tests and sex licenses...
But yes, it's imperfect. The age of consent is primarily there to prevent older people from taking advantage of less world weary younger people, and that is a noble thing to try to prevent. Unfortunately, you can still end up with situations where older people are child-like and naive, whether it be due to extreme age, mental handicap, lack of education, other considerations... plenty of times one adult emotionally manipulates and takes advantage of another.
So in conclusion, the laws aren't perfect but they are attempting to do positive things. I think the answer to the flaws in them is to give judges more leeway in sentencing for weird cases, and have judges who have some common sense. Judges who can dismiss a case against an 18 year old boy sleeping with a 17 year old girl. etc.