My background (as you know

): PhD in engineering - applied physics. 5 years as a postdoctoral researcher. Recently switched to working in industry.
Fun fact - one of the last projects I worked on as a researcher was related to the interface between the body and hip implants (not from a tribological perspective, though).
A PhD is hard work. Really hard work. I would really not recommend starting one just to get the degree. Your research is basically your life for three years. If you are not all that interested in the topic, it will not be enjoyable.
It is perfectly possible and indeed normal to use a PhD as an approach to a career in industry. Quite rare to start a job and then get a funded PhD later, though.
I'm no expert on tribology, but it's a quite broad field. Certainly applicable quite widely outside bio. Many places will also happily hire engineers with backgrounds slightly outside their application area. Engineers are good at learning quickly.
My suggestion: Delay the decision until your daughter gets some experience with her major interest. This PhD might be gone, but there will be others. And if this supervisor in Luleå is really that good, he'll probably have some new funding available next year.