as mine just turned 6 and she knows she is not allowed to watch Doctor Who series (adults series) but Sarah Jane Ad is similar to D who and my dd1 said its really good and is not scary. I just thought its a childrens version of D who, till i saw it this afternoon (ive never really watched it properly), there was a Lord Voldemort look-a-like (out of Harry Potter) was on, but worse as it had fangy teeth and no eyes!! eeekkkk!!
It was only cos my mum by chance was visiting and said the SJ adventures is scary and i said "Dont be silly mum, its not!", till i saw it 
am i over re-acting for my 6 yrs old??