Hi all - first post here: I just started on Fundamentals 1 and I am practicing Lisa McCormick's "spider legs" warm up. I'm doing OK with the fretting and even getting a passably decent tone without catching adjacent strings. But here's my problem: When I'm reaching up to fret the low E string, particularly with my index or middle fingers, my palm is catching the high E string and muting it. I keep trying different thumb positions to see if that helps but I'm a bit worried that I'm just not anatomically inclined towards the guitar! I have relatively short fingers and wide palms, and it just seems that to get enough reach to fret low E and leave A open, my palm nudges up against high E.

Any advice? Is this a common problem for beginners?