Baby's decline in time on boob

Alexandra

My baby is 6.5 weeks old, and has been feeding less and less every week. Attached a photo of the time trend. She has green poop, which I'm thinking is either she is only really drinking non-fatty milk (not finishing my boob) because she likes to nurse for 5-7 minutes then stop during the day. At night she seems to mostly nurse for 20 ish minutes, but not really during the day. She also goes shorter between feeds during the day. Or the green poop could be a sensitivity to something in my milk (I am vegan, so it's not cow's milk).

I'm worried my breast milk supply will swindle to the point I won't have enough to feed her. She is still exceeding the number of poopy diapers and wet diapers we are to expect in a day (6+ poopy, 7+ wet) so I feel like she is getting enough? We haven't weighed her since 1 month.

Anyone experience a part of this and can reassure me that some or most of it is normal? I had asked for a follow-up lactation consultation after the hospital, but because my baby latched so well in hospital they didn't give me the appointment that I could have used for peace of mind now...