I think it would be fine to tell her that, as you ready for your move, you'll keep an eye out for the items, and when/if you find them, you'll let her know when she can pick them up before you move.
I can see her expecting that you will either deliver them to her house, or that you will move them to your new home so she can get them at a convenient time...say, in another couple of years. Neither one should be an option. If these things are important enough to her that you should make a special effort to find them when it's NOT convenient for you, then she should be expected to inconvenience herself a little to come get them when you DO find them.
I moved into my current house in late July, but I actually rented the house in mid-June. It was vacant at that time. After I'd been here a couple of months, a guy knocked on the door and said that he was the previous tenant (he gave the name of the previous tenant, which I knew because of misdelivered mail) and that his girlfriend wanted back the pots and pans she'd left behind when they moved out. Four months earlier. I told him that there was nothing in the cabinets when I'd rented the house. He muttered about the landlord stealing their stuff. Seriously. He also asked about assorted stuff he'd left in the garage, including a workbench he'd built from scrap lumber. I told him that the other items were not in the garage when I rented the house, and that I was using the workbench as storage shelving. (I only admitted it was still there because it's visible from a window). I wanted to say, 'Sir, you should have taken it with you when you left. At the very least, you could have carried it out of the garage and left it in the driveway, so you could come back and get it at your convenience during the weeks prior to my moving in.' (we had a horrible drought last summer, there was very little risk that it could have been damaged due to rain during that time) There was no way I was going to go out to the garage and move all my stuff so he could get to it...especially since I could see he didn't have a suitable vehicle for removing it! I suppose he expected me to make an appointment so he could come get it...whenever. I was not about to have it standing in the driveway for me to drive around...