A few questions about my chihuahuas ears not standing up?

she is 8weeks old and i got her last week, her ears sort of flop. like she is holding them up, but their is a crease along them quite low down, so they just hang over, all the other puppies at the house had the same ears, is it normal for them not to stand up yet? and will they stand up soon? is there anything i can do to help them stand up? i hears about massage... how do i do it?