Raising sons is a treasure that one can only appreciate if they have the battle scars to prove it (not meaning the stretch marks that all babies give mom). Like grey hair (at a young age!) from watching them jump from the garage roof-thinking you're not looking or bringing in a mouse they've caught from the yard or a snake, etc. You get the picture. There's loud music, instruments, dirty underwear contests, dangerous stunts, dives, 'girl's are the devil' mentality that lasts for years (but not forever!), and so many other things that separate boys from girls.
It's a different kind of mother's love for her than the boys, but it's still mommy's love.