My sister is loved more than me?

So im only 12 should not be feeling this way but i feel like my own mom dont love me. i dance and every time i ask her to watch me and tell me what she thinks she says i will be ther in a min sophia. 20n mins go by and i say mom come watch and she says again one second i walk back and shes layin in her bed on the computer.so i walk away and go practice more than my older sis who just turned 17 will ask her to come her to look at her gsp thing and she will go right to her . why is this is it something about me please help and if you have nothing nice to say than dont say anything at all.