Crawl under on a Harbor Fright Tarp. Cheap Blue one. Then she can slide you on it, or it on the ground. I slithered under ours to check something and found I don't crawl (on my back..) anywhere near as well feet first as I do head first. Although both are kinda comical. My cousin grabbed me by both ankles and pulled me back out. On gravel. I should have planned ahead with a tarp.
At home, I really like cardboard. I keep a couple large boxes that I've flattened. Home I have a concrete RV pad, and it's amazing how much more comfortable (less uncomfortable actually) the cardboard is than just being on the concrete. I have a mechanic's creeper, but that takes up too much of the limited height under there. And, I find it lets me move when I'm trying to tighten or loosen something, when I need to stay put.
Crawl under with a phone and key "91" into it. Then you'll only have one more "1" to punch.