Katy Perry headed back to American Idol six weeks after giving birth — and her fiancé Orlando Bloom’s ex-wife, Miranda Kerr, couldn’t be prouder.“MUTHA MILKS is back to werk @americanidol and it’s udderly ridiculously MOO-ving already ” the “I Kissed a Girl” singer, 35, captioned a Thursday, October 8, Instagram slideshow in a cow-patterned dress and matching hat. “Not pictured: my pumping breaks.