CCTV Camera or Ring Doorbell (Kettering NN16)

Dear all,
A little old lady, a local client of ours, is being harassed and pestered by unwanted callers, some of whom are apparently very aggressive and persistent.
She is not in great health and finds the intrusions extremely distressing.
As she also receives visitors (friends and relatives) from time to time, she is afraid NOT to open the door, in case she misses a genuine caller.
A small CCTV camera or Ring doorbell would be perfect for her to see who was at the door, before opening it and subjecting herself to unwanted sales talk and similar.
I'd be very grateful if someone can gift her a CCTV mini-cam or even an old Ring doorbell, or something of that sort, which we can arrange to fix outside her front door.
Please email me on peteranderson1958@gmail.com if you're able to help.
Our charity website is here. https://peteranderson1958.wixsite.com/website-1
As we are perennially short of volunteer drivers, delivery would be much appreciated.
Cheers.
Pete