Martha Washington

To find out what someone well known looked like, go to Google, click on Images at the top of the page, to go to their image search, type in the name of the person you are looking for. For Martha Washington, we get a few of her as a young woman with dark hair pulled back, no head covering, and an expensive looking long, full dress that looks like it it made of silk or another silky looking material. As an older woman, she is most often pictures with a hat or head covering of some sort, but not a large hat. Her dress is usually dark with a wide white color or scarf around her neck.

Then I went to google.com and typed in What did Martha Washington wear. I found this site,
http://www.history.org/history/clothing/women/wglossary.cfm
A Colonial Lady's Clothing: A Glossary of Terms

It should be helpful with fixing a costume.

So, if Kenzie wants to be a young Martha Washington, she should pull her hair back, put it up, and wear a long, full, fancy looking dress with long sleeves. However, if she what to be an older Martha, she can powder her hair with baby powder to make it white, put on a white (or maybe off white eyelet) ruffled bonnet that just covers the top of her head, a dark long full dress with a plain white collar or a plain white scarf around the top of the dress. I vote for a mature Kenzie Martha.

A white ruffled bonnet with elastic to poof out over the top of her head should be easy. And, powdering the hair should make it look white or at least not red, red. The dress has to be long and full with sleeves at least elbow length if it is to be correct for the times. The sleeves can be lengthened with ruffles.

Here:
http://www.history.org/history/clothing/designcenter/timeline/
is a Williamsburg VA site that tells about how the costumes at Williamsburg park have evolved over the years. It gives good descriptions of what was actually worn in Colonial times.

You go Gone with the Wind and make a fancy dress from a silky curtain.

Then if you type Martha Washington Costume in googe you get this.