Hello Anne and welcome to WikiTree. The best way to find out if Elizabeth de Ferrers is related to you is to complete your WikiTree membership and add your ancestors. Since you are still a Guest you have limited access. Go to your profile or navigation page and click on the Upgrade link (completely free to upgrade). Just follow the instructions to become a Family Member. A greeter will then post a message to your profile with a link for very helpful links on WikiTree.
Then you can begin adding your parents, grandparents and going on back and eventually you will probably find that some of your ancestors already have profiles on WikiTree. Hopefully, you will be able to figure out if you are related to Elizabeth once you have some ancestors entered.
Good luck with your research and please ask as you have questions.