Kelly Osbourne’s latest Instagram post featuring her blonde son has sent fans into a guessing game frenzy, as they speculate over which famous singer the little one mirrors the most. Kelly Osbourne recently charmed her Instagram followers by sharing four adorable photos of her son, Sidney Wilson. The pictures captured a sweet moment between mother and son, with Kelly in a mushroom-patterned top and Sidney dressed in cute sailor attire. The proud mom captioned, “I love nothing more than being your mother! You are the single best thing to ever happen to me. Thank you for being my baby!” The hear…