If your routinely dating / sleeping with her she should really just be sending them naturally & by default
My last semi serious situationship would send me stuff at least 2-3 times a week , her in lingerie , playing with toys sh1t like that
She liked the thought of arousing me , most women are going to enjoy doing it for you
Girls your casually talking too and not regularly sleeping with its a different game , she has too trust you a lot and you have to subtly assure her that they are going to be for your eyes only
I have a catalogue of old pics from girls that I may show to close freinds occasionally to make a point but I would never fully share that private content