My late mum knew a lot about dreams and dreaming. She would've said that the dream the girl had of someone chasing her with a knife and being weighed down by a heavy stone would've meant she was afraid of someone trying to stop her reaching her dreams and the stone is her being weighed down by either her own worries, or even emotional blackmail ('guilt tripping') by those she feels are trying to stop her achieving her goals. But this is just my opinion, based on my mum's knowledge, so of course other people can think differently. 😊