Sas- it sounds to me like you are doing a great job, i would try not to listen to your mum's advice that its a starvation poo (unless she is a paediatrician of course!)

My 10 week old DS has had quite a lot of green poo's, usually when he has been quite windy and not burped so well after a feed. They have been a bit mucousy lately too and as he has a bit of runny nose at the moment i have just put it down to that.