lol - I know all about that at the moment - even though she has no 'specific' shape - she is all legs, then body, then head, then tail at all different times

Wow - just reading this.

16" at 4.5 months. And now about 19" - 19.5" at about 7 months

So.. Any more predictions on her final size? I am taking bets

That could be a bit on the small size for a Newfi again some dogs of the same breed will finish their hight growth by 7 months others will continue getting taller until about 14 months, most will not get any taller after 10 to 12 months. Dogs that have been castrated early are on average taller than they would have been if they had been left intact until all growth had stopped, and may continue growing for longer.

There is no such thing as normal for living creatures, so much else can interfere with the normal process and that is controlled by the animals genes and hormones. The genes provide the blue print and the hormones switch the animals systems on and off as require, that is simplistic, of course, but I think you will get the idea.