pic #1 , agree that its not sharp. You probably answered it yourself, lower light condition, shutter speed dropped too much. You in aperture priority mode? Up your iso, or get closer to the woman, so that you can shorten focal dist and use larger aperture. That makes the background more blur too.
pic #2 , looks sharp too me leh. Unless you're pixel peeping at 100% crop. You'll need a prime lens to go even sharper.
pic #3 also seem pretty alright.