The indie pioneers of Williamsburg will not let young parenthood spoil their indie-rocker cred. That is why so many of them are naming their kids things like Cash and Marley, giving them Ziggy-era Bowie haircuts, putting them in toddler-size AC/DC T-shirts and taking them to the new Frolic! play space, a 5,000-square-foot, candy-colored facility in the waterside Edge apartment complex. With membership nearly $1,000 a year, the space — which features an array of music classes, its own in-house band, a slide built around the famous Rolling Stones lips and a “Ziggy Starbus” VW minivan — allows parents to steep their kids in a wee version of rock culture while they kick back, drink organic coffee and reminisce about their Cobain- and DiFranco-worshiping wild years. We stopped in recently and asked a bunch of moms (and one dad), all from Billyburg, if and how their own kids are exhibiting signs of Mommy’s bad-ass halcyon days.