Early 2015 MacBook Pro OS not updating

Hi all

I am writing to inquire if anyone might be able to assist me. My mother owns an early 2015 MacBook Pro, which she primarily uses for streaming services such as Netflix. However, I have encountered an issue where I am unable to update the operating system beyond OS X Yosemite. As a result, none of the browsers I have tried will update their software, rendering them incompatible with Netflix. Is there a solution to this issue, or would it be advisable to purchase a new laptop for my mother?

Thank you for your time and assistance