Help! Breastfed baby has consistent green poop

My baby girl is 6 weeks old, and for the last couple weeks, she has had consistently green, seedy poop. I took her to the doctor on Monday, and he checked her vitals, and told me if it hasn’t gone back to seedy yellow then to give him a call in a week. I read that green stool can be a lack of hind milk, or an allergy to food (mostly cows milk). I have been off all dairy products since Tuesday and no change. I read that it can take 2-3 weeks for cows milk to get out of mothers system so I shouldn’t expect change for 10 days to 2 weeks. What else can be her issue? She seems extremely happy and healthy otherwise!