My hair also grew in a bit like baby's fluff at the beginning. The top also grew back a lot slower than the sides. From talking to others, slightly odd hair growth is completely normal until your hair is about 10cm / 4 inches and then it starts coming in more or less as it was.
This is something that is entirely up to you. Many women do shave their heads because they prefer that to the gradual falling out of the hair. I don't kinow that it would encourage any better hair growth but most seem to be more comfortable doing it that way. Regards ..