Daughter Broke Her New Laptop

GDB2222

It’s not usually worth trying to repair a motherboard, so I’d check the cost of a new board, then sit down. Then, claim on the house insurance. 

The first part of that process will probably involve getting a quote for repair, so yes take it in for a quote, but be prepared for a charge just for quoting!

You mentioned a possible repair cost of say £200. That seems highly optimistic. On a lot of these thin machines, almost everything is soldered to the motherboard. Processor, RAM, and on Apple even the SSD. It keeps manufacturing costs down, and makes for very sleek designs, but makes even minor repairs prohibitively expensive. 

Withbellson

My first port of call would have been Lenovo. They are best placed to do the repair in the first place. Added to that they may have something in place to allow you to purchase an accidental damage cover retrospectively, in the light of it being a new device.

When I bought a Lenovo laptop, I went to the Lenovo website to register the warranty, which then gave me the option to extend the warranty, which I did. 
https://www.lenovo.com/gb/en/services/pc-services/lifecycle-support/warranty-protection/

I am slightly concerned that you may have voided the warranty by messing around with that screw.