Hi! I've looked at lots of kids bedroom designs over the last few months and most of them have window seats just like this but I've no idea how to fit them or buy them. Does your window have to have a low windowsill for this to work? Because that's always what I've thought has to happen, but now I see yours and you don't have a very low windowsill. So a bit confusing for me, but could you let me know the procedures of buying and installing? Thanks, merry Christmas!