My grandmother has distinctive handwriting and I’d love to turn it into a handwriting font. There are online services that will take your handwriting and convert it into a font for you. Some are free and some charge for their services. I have yet to try this even for my handwriting but it is on my list of things I want to do. It will be a little more difficult to do it for someone who has passed on because you will either need to trace their handwriting or else do some scanning and cut and paste to get the needed characters. Below are a few links to guide you along the process.
Make Your Own Handwriting Fonts
Tips on making a handwriting font
telling family tales 