I still don't have a Jenny doll, so I can't promise the patterns for clothing work for MH or EAH , but this book was made all about hair styles. Though it's all in Japanese, and the poster may be Greek or Russian, there are loads of illustrations with the directions.
I figured that the braided styles may help modders that have damaged doll hair and are not ready to try re-root yet. There are also methods for hiding a bald spot to make pig tails that may come in handy.
I had some Jenny dolls many years ago. If I recall she is very close in size to Barbie, except that her bust is a bit smaller and her waist might have been a tad thicker. MH and EAH are shaped quite differently.
The book looks really interesting. Thanks for sharing the link. I have a few dolls which are in dire need of hair makeovers.
I do with some had a few more diagrams some of those look REALLY complicated!