a friend of mine also works in the same line of work. she also isn't qualified as a nurse so perhaps isn't the earning as much as she could be. considering how hard the work is, she isn't on a great deal (around the 15k mark as she is assistant manager). one of the other problems she has is that her employers frequently call her in when she isn't due to work (although that could be an excuse she gives me :D ).
on the positive side there is plenty of work about if this job doesn't work out. as dave says don't rely on other people to back you up if you plan of saying something to your boss. i've had people say that they would back me up then they go all spineless when it comes to the crunch.