The other thing I've seen from time to time is that sometimes you'll get leagues who have one-size-fits-all goalposts to try accomodating all ages, where the goalposts split the difference between youth and adult players, which causes the goal to be too small for older players. For players 12 and up, the goal really should be FIFA standard-regulation 8 feet high by 24 feet wide - anything less is just asking for trouble.
Unfortunately, more than a few refs do little to protect the keeper. Their attitude seems to be that if my daughter is "stupid enough to play goal, she has to be tough enough to take what she gets." The girl that kicked my daughter square in the head should have been red-carded, but didn't even get a yellow. If she could legally play soccer with a combination catcher's mask/NFL helmet on, we'd have her wear it!