Is She's in Too Deep?

I suppose maybe a bit more of a cockney accent, and maybe in some places in the north of england as well. I don't tend to do it a lot, but i think some people would. And then the other thing that was really interesting that she says here's in the deep end. What is that referred to? So if you're in an area where your feet can't touch the bottom or something like that. There's another very similar expression: To be in over your head. It means the same thing too when you're going through a heart break.