I'm sorry to hear about the loss of your grandmother and I'm sure her doll is priceless to you no matter what her monetary value is. But I do understand the desire to know what you have. There are many websites devoted to dolls to help you Identify them and ebay is the best source to find out current market value.
But first of all you need to know what terms search with. I wish I could see a picture so I could help you more. (you can email me one if you want) because there were no plastic dolls in the early 1900's, unless it's celluloid (which is very thin & fragile) Most dolls of that time period were made of bisque and then later, into the1920's & 30's dolls were commonly made of composition.
Celluloid dolls were popular from the 1920's into the 1930's as well. If it is hard plastic it would date from the late 1940's - early 1950's and if it's vinyl or blown plastic it could date from the early 1950's until present times. If the doll has a glued on wig it is most likely hard ... more.
I cant really gove you an answer,but what I can give you is a way to a solution, that is you have to find the anglde that you relate to or peaks your interest. A good paper is one that people get drawn into because it reaches them ln some way.As for me WW11 to me, I think of the holocaust and the effect it had on the survivors, their families and those who stood by and did nothing until it was too late.