steel vs Plastic strings

I've been practicing about 2 hrs a day for almost a week now and still cannot get the same tones as Lisa. I play the exact same note exact same strum ( as far as I can tell ) and not the same tone. I noticed tonight she is playing with all steel strings my bottom 3 strings (123 or EBG) are PLASTIC. is THAT THE DIFFERENCE. to get the same tones I wouldnt mind getting new EBG strings if that would fix the problem

In the other post you mentioned you have classical guitar. Those have nylon strings, and the sound is very different from steel string acoustics.