Sister, I've gone through exactly all that about clearing the house of images and things. My mother had little porcelain dolls in the drawing room showcase, and some utensils with images on them, and also photoframes around the house. You will have to give dawah to her again and again. I tried for years and now alhamdulillah, my mother herself tries not to have any images around.
It was difficult at first, but try different angles, try and tell your mom angels won't come. If angels won't come, then how will blessings etc be sent to your home? How will dua be granted? etc etc. Wait for the right situation and use it to your advantage. Once, my mother was a little disappointed with some events in life, and she was wondering "why did so and so happen?" and I quietly advised that maybe Allah doesn't like all these images in our house, so how will we get barakah, etc.. It worked. Try it, sis.
Plus, go around and remove the things yourself. It's okay, you'll be scolded the first time, second time, third time, but inshaAllah keep giving dawah and quietly removing the photos and they'll get the message. It's actually even mukrooh to pray in a room with images around. So try praying in each room and go "oh no, prayer won't be completed here!" so you'll get an excuse to remove the unwanted materials.