I'm sitting right here. Yes, you are not related to them and never met them and I didn't meet them either HOWEVER they are /my/ relatives and I'd like to see what they look like. My siblings may want to see what they look like. GRANDKIDS MAY WANT TO SEE.
I mean we've been over this and over this. "I don't know them and I don't want to store the photos" is a reasonable desire. Destroying family records, denying your children and future generations access FOREVER is not. Back the F off. Don't get pissed at me for getting pissed at you. Hand over the damn pictures and no one gets hurt,. Pretty GD simple
Truth is she never liked her inlaws. That's still no excuse to expunge the records. IMHO.
(In my defense I did not immediately get pissed. It nearly always takes the third time of my saying the exact same thing that gets me pissed. "I'd like to see them.")