I think she does use that Podreel program that was mentioned. I looked at it myself, but I believe the trial watermarks the finished podcasts, which is obviously unsuitable for us, so you would have to pay for it.
That's right, the trial version of Podreel's limitations are a watermark at the end of the file and a limit of only 5 chapters. Thankfully the full licence is rather inexpensive as it costs $25 (or £16) to remove those limits.
I got the recommendation for that software from Whooa21, whom might be knowledgeable on other forms of chaptering programs; though even then getting his input may be tricky.