She will have been moving since she grew limbs, but your uterus can't feel it. You'll only feel it once your uterus is pressed up firmly against your abdominal wall, and the nerves in your abdomin can detect the kicks.
This point is usually reached at around 18-19weeks but can be later (or a bit earlier if your uterus is large). You'll start to feel flutters and nudges any day now. If you still haven't felt anything by 24w mention it to your doctor.
Usually around 20-22 weeks for your first baby. Chances are she's moving and you don't even realize it's her