If that works for her, that's the course she should pursue, but I'd like to put in a few plugs for the rejected venues.
Conferences are islands of opportunity for networking with other writers and learning all kinds of interesting tidbits about writing, publishing, promotion, and marketing. Sometimes you have an opportunity to pitch an agent or a publisher, and that pitch might morph into a contract. The biggest perk for me is the people I meet, whether for the first time or the dozenth. Someone once said/wrote, "I am a part of all that I have met," and it's true. People are our greatest resource. If they buy our books, great. If they tell someone else about our books, terrific. If they do neither, we're both still richer for the interaction.
Book signings typically don't do well. I say typically, because some of them do net good sales under the right circumstances. But again, it's about people. I did a book signing once where I didn't sell a single book. It was late in the day, and I'd been placed in a rather out-of-the-way corner. But what I did do was have the opportunity to talk writing with a young person still in high school. I hope perhaps I gave her some good advice, but what I know I did was encourage her. She had my undivided attention and my assurance that she was a writer now and could be a writer in the future if that's where her dreams lay.
As for speaking, I have to go back to that tired old word--people. Who knows if you'll touch a chord with someone? Maybe you'll even get the whole symphony playing in their souls! When I go to hear a speaker, I take out the ever-present notebook and write down all kinds of gems which find their way into my writing notebook.
We all want to sell books, but there's so much more to being a writer. To trot out another cliche, "No man is an island." No writer is either.