To your specific question - no.
My seven year old daugther’s email account gets plenty of porn spam. She has her own machine, and has never been online without my constant supervision. I know that machine has NEVER visited a porn site. But she gets plenty of offers to lengthen her penis.
There may be a connection between visiting porn sites where you have entered your email address, and porn spam. But it certainly isn’t the only reason.
And btw, I have an email account I setup for my wife over a year ago. It has not received a single bit of spam. The difference? Mainly that her account is setup under a very rarely used or noted domain. My daughter’s account is setup under attbi.com. And while her is user name isn’t particularly common, it is apparently common enough to make the spam lists.