Sounds like Maya's doing great!
It is so hard to tell, isn't it? I used to wonder if Natty was getting enough too, but after I while I just stopped worrying. As Feeb said, if she is gaining weight (even slowly) and weeing then she's getting enough.
IRT the letdown, I didn't feel mine until Natty was a couple of months old. And I didn't feel it every time either.
You're doing awesomely.