Discovering hands

Baby is 3 months old and has still not discovered hands. I see that this is considered a red flag but what does it mean???? I’m a ftm and super worried!

Also, what should I be looking for to know if she has discovered her hands? She puts her in her mouth all the time, but doesn’t bat or grasp objects yet... any experiences with this? Will talk to pediatrician when we go in in 2 weeks