I had a friend who went through this, basically at the nuchal fold scan they measure the thickness of the skin on the back of the babies neck and if it is out or something they will want to do further tests like an amniocentesis, which is just when they numb some of the belly and stick a needle into it and take some of the amniotic fluid for testing, my friend also found out from this that she was having a little girl. If you google it you will find heaps of information on it. I hope your friend isnt to worried as hard as it can be.
PS my friend gave birth to a beautiful healthy baby girl last weekend so tell your friend that even tho the scan came back funky it is possible to still have a perfectly healthy baby