What makes you think that your cookie jar is over 100 years old? Ceramic cookie jars were produced in the USA in the 1930s. If you are trying to learn about your item, you need to use clear terms in your description. Include the material it's made of, the size, color, and decorative features.
Look for the maker's mark on the bottom of the piece.
Before you can learn the value, you need to identify the cookie jar, who made it, and its age. The value will depend on the condition. Cracks and chips will devalue any older item.
You may find it difficult to get someone else to do this work for free. But you can do this yourself by looking at a book. Older books will not reflect current values but will help you identify your cookie jar. Look in these books to see if your piece is included:
"The Complete Cookie Jar Book" Schiffer Book for Collectors
"Ultimate Collector's Encyclopedia of Cookie Jars Identification and Values" by Fred Voring and Joyce Roering.
There are many books on cookie jars, and you may find one used or you can look in your library. Then, sign up on a site like Replacements, Kovels, or Worthpoint for help in finding the value. You can also look for online sales and check out the sold prices.