I just bought an 8 week old female pom and took her to the vet who said her skull is still open. She recommended an ultrasound to check for fluid on the brain. THankfully she did not have this and the vet said the skull may still close (or may not) and may still possibly become a serious problem. Does anyone have any experience of knowledge of this? (I did not read about it in any of my books or in my research online. SHe acts perfectly normal, eats, plays, sleeps and has adjusted to her new home very quickly.)

I hope everything is going well with your Pomeranian.
A open fontenelle will often close as the puppy grows up. In other cases it may only get smaller and I have heard of dogs with open fonts living long happy lives, so try not to worry.
Things will be fine.
Hugs
Denise