does anyone know if this is a hen or roo???

We will need a full body shot that shows the bird in side profile so that we can see the entire bird. Also, you have had it for 6 weeks (give or take) but how old was it when you got it - if you are not sure tell us whether it was fuzzy like a day-old chick, feathered on the wings and a little on the chest but not the head or feathered all over with no fuzz anywhere -- age is very important in sexing immature birds as characteristics that can mean pullet at one age can mean cockerel at another.

 

Looks like a pullet to me. Orpingtons can fool you, though, and not knowing the age makes it harder to say pullet for sure.

 

possible pullet - the best I can do

 

It was well feathered when you got it, track another month an a half (time you've had it)on to that and I'd feel safe saying pullet.