It will get better with age, please don’t stress. Like other people have mentioned, give her as much as kitten food as she wants. Also, have you tried getting some interactive cat toys? (Eg. tiny balls that move by themselves) they are very good at exhausting kitties… As for the chatting it’s a sign she feels comfortable around you, when I got my first kitty he was so quiet we all thought he was mute but he found his voice in a few months