Glint Weaver’s Effect says when it enters, your creatures get +1/+1. Then: you gain life equal to its power. However, it only gives +1/+1 to your other creatures. If I cast a second copy of Glint Weaver to reinforce it, it still doesn’t buff itself.
Battle Log:
Glint Weaver was triggered.
-Player- Gain Life: 3
…
Glint Weaver was triggered.
-Player- Gain Life: 6
If Glint Weaver enters, and it’s the only creature I have, I don’t gain life, presumably because the team buff didn’t resolve.