No worries, Ritin'. I've spent a lifetime with folks getting Quakers mixed up with others. Each religious sect has key differences, you just have to be sure of the ones you're going to write about.
Which sort of leads me to ask, why IT? I'm guessing it's because you're physically there (based on your avatar info), but is it the "right" area for you to set your story? I have to say, I've heard your description of what happened to your grandmother -- given the day and age, I think it's a fascinating story. Women were rarely allowed to own property, they were denied rights we consider basic today -- and here is this woman whose relatives leave her off to fend for herself when her husband/their son dies? I think that she survived and clearly prospered is potentially a GREAT story. She was alone, in hostile territory (because most of the West was hostile in those days particularly if you were a woman alone with a baby or small child), and managed to succeed and become a matriarch? Again, to me, that's a fascinating story, just begging to be told.
You're not going to be able to avoid the research, no matter where you set the story. Historical readers are notorious for their attention to detail. It's part of why they love reading historicals -- to learn something new, to find a writer who loves and brings alive whatever period for them. But they are very quick to go check a fact and verify an assertation, and if you're wrong too often or too early, it's all over for them. So, research is going to be a part of your writing life, if you're going for realistic historical fiction of any kind. Ergo, choose the right area for your story, and do the research. It will take a bit longer, but it WILL be worth it (says someone who now knows a whole lot more about the Old West and all the aspects that made it up than she ever thought she would or would need to).
Anyway, I throw my vote in for your grandmother -- she sounds like someone I would truly be excited to know.