By Megan Feringa Chelsea Women boss Emma Hayes expressed disappointment that her side couldn’t put a second goal past Barcelona in their Champions League first-leg semi-final win on Saturday, noting the fragile margins at play against the current holders. Captain Erin Cuthbert’s first-half strike gave the Blues an important 1-0 advantage as they return to west London for the second leg next weekend at Stamford Bridge. Chelsea required some time to settle into the match in a hotly-contested match between two old rivals but produced a solid performance to grind out a narrow and deserved win on t…