Remote training person here: she should start by taking a course on adult learning (doesn’t need to be a masters or anything, just something she can add to the CV, something like https://www.udemy.com/course/training-essentials-of-adult-education/. There’s a lot of stuff out there for train the trainer.
And then learn some elements of instructional design: lots of online courses for this, here’s one: https://www.coursera.org/learn/instructional-design-foundations-applications
Practice a little bit, get familiar with some tools for online learning, spend some time exploring different Learning management systems.
Google also offers a lot of content that could be relevant: https://rework.withgoogle.com/subjects/learning-development/
There’s also a r/training subreddit that can be helpful.
Best of luck to her!