Ask HN: Is there a way to use the iPad Pro as a desktop PC?

Thinking of buying the new 9.7" iPad Pro for my wife to replace her old iPad. I'm wondering if it could also replace her old Windows PC. For "lean-back" tasks (email, reading, etc) she loves the iPad. For web surfing, online shopping, web videos and occasional spreadsheet, she prefers the PC's 22" screen and a physical keyboard.

Is there a way to send the iPad's screen to a 4K monitor via the Lightning connector, and turn the iPad's screen into a multi-touch trackpad. I know iOS doesn't support mouse cursor so the GUI would be a problem. Does anyone have a creative workaround (without jailbreak)? Thanks for reading.