Geez! Just go over there with some containers of extra breast milk and give L a big hug, and then tell her that you are there for her and her baby! Tell her that being depressed is not her fault - it's just hormones affecting her brain. Tell her that you care about her and it's not a competition - your babies are brother and sister and they need their mommies to take care of them and each other. Don't be afraid to step up and make it known that you only want the best for her and her child! Step second-guessing yourself and deferring to G, you can rebuild your friendship with her yourself! Do not hesitate!
The world opens up... when you do.
Oh, oh, can't you see? Love is the drug for me. ~Bryan Ferry
"Love is that condition in which another person's happiness is essential to your own." ~Robert Heinlein