1. Don't use anything Microsoft, use Figma or XD. Figma is free for individuals, and XD is part of Creative Cloud.
2. This is a good start, but if she wants to get into UX she should start by reading articles at Neilsen Norman[0], UX Planet[1], or Interaction Design
3. See #1, although frankly it pays to do wireframes on paper before even touching a mouse/trackpad.
4. I would say at this point that HTML/CSS is a "nice to have" skill. I believe that Figma now contains a basic interaction design suite (i.e. tap, swipe, scroll) that lets you go between different screens.
5. I'd say to stick with learning how/when different charts should be used rather than trying to jump into something like HighCharts or D3.