Article writers who have a lot of themed content on various web sites have enough for a book, if those articles are nonexclusive to the site you first put them on.
If you write parenting topics, I bet you could group them together in sections to provide a parenting handbook. There is a lot of completion out there for parenting topics so you would need to focus on a specific topic such as parenting a special needs child but it could be done.
Did you know that Amazon would allow you to upload a file free in there Kindle section? Of course it has to be the right type of file but that file with the right info could make you some serious. The beauty of a Kindle book is that it does not need to be the size of a regular book as far as word count goes. 20k is a good minimum to start for an ebook.