Need help!! locked out of laptop, 4 digit pin or firmware password lockout

Hello apple community,

My wife has been locked out of her macbook air 11inch, as we turn on the laptop it takes longer then normal to turn on, after it turns on a screen with red letter states "your computer is disabled. Try again in 5 minutes" after the 5 minute wait there is a 4 digit pin (passcode) which she never set. long story short, we have not used the laptop for 2-3 weeks due to fatigue in her third tri-samester. After Giving birth to a healthy baby she noticed she has been locked out of her laptop and since then asked me for help. I purchased the laptop on craigslist in 2012 and do not have a purchase receipt. I made an appointment with the apple store here in socal and there is nothing they can do since we do not have the original purchase reciept. We also lost contact with the seller (purchased in 2012.)

at the apple store, we tried logging in through icloud which we had no success, and we never set a filevault or never used the "findmymac" app. This situation is very unusual since we never set a firmware password which the apple store insist we must have. We are out of ideas and we need to get this laptop up and running again, she has a lot of important files inside for school and work.

Apple community please give us some assistance as we are out of ideas, We spent 2 hours at the store trying to explain our situation but due to their privacy policy they will not be able to unlock the laptop, the only suggestion they were able to give us is to purchase the laptop brand new from a apple retailer.

I believe there must be some sort of special circumstances to bypass this rule, we spent 1200 on this laptop in 2012 and I believe our finances can go elsewhere instead of a new laptop.

Thank you for your help in advance