Could you ask them to go their local lv store, have them pick the bag, and then do a wire transfer to their account? Bags are personal items, so I would let your relatives do all the picking and choosing. What you think may be a great bag, could be something they hate. I'm no where near 65, but if I don't like a bag that someone has gifted me, I either don't use it, or I give it away.
Speaking of age, at 65+ some women will start to feel the effects of aging. Some women will prefer one bag style over the other because of their joints. Other women may need to carry more items for health related reasons, so they would prefer a larger bag, or a bag that has the "perfect" easy access for them. My grandma has been gifted luxury bags from her children, and she doesn't use them if they don't work for her. She doesn't care about the brand. If she's not happy with it, she won't use it.
This is an expensive purchase on your part. Even though it would be nice to surprise them with the perfect bag, I think this is a case where the more thoughtful thing to do is to let your gift recipient choose. Just let them know your budget, and if they want something out of your budget, they can pay the difference.