Great thread! I'm 4'10", but quite strong for an old lady. I do everything on my farm myself, from carpentry to mechanics to stacking hay, but I do it kind of slow, and in smaller bites than your average bigger person. I haven't seen the height and reach issue addressed here yet. Everything from grocery store shelves to normal height carpentry is about six inches out of my reach, which is on the extreme end of things, but many women work in a world sized for taller folks. As a great tactic to avoid using a ladder all the time, try a really sturdy milk crate. You can move it easily, it's stable, even outside if the ground isn't super sketchy, and you can use it as a mini sawhorse too.
Having a tool that I'm not fighting makes a huge difference! I use Makita 18v cordless tools a lot, and they have served me well. They are very light, and one thing I appreciate about cordless tools is when you hit a dead stop with a drill, say, they don't torque so hard it tweaks the wrist. Corded tools cause me more wrist problems, I find. I can't take the batteries off one handed either--my hand span is smaller than they are designed for. For all tools, especially power tools, you have to learn to use them safely! I'm not much for getting help, but do find someone who can show you simple rules like keeping your fingers tucked in when hand sawing, or positioning yourself so if a tool slips you are not in the line of it. It's really dangerous to use a tool that is dull or that you can't really control. If you can't rig it up safely, walk away and think about how to do it a different way. Every time I've hurt myself it's been when I thought I'd "just go ahead and do it this once".
I cut handles off to the right height on lots of tools and also shave them down to a better diameter. If your shovel handle is too long it can whack you in the jaw! Yes, keep tools sharp! Learn to chainsaw on a small saw first, to learn how to do it. My neighbor swears that cordless chainsaws are much safer and lighter, but I've yet to try one. I can handle a middling sized saw now, but have a very clear sense of my limits. On the subject of anything with a pull start, shorten the pull cord so the moment when you have to use force is not when your hand is way up above your head somewhere, but down where you still have some physical advantage. Electric start tillers and generators are great, but it's good to be able to pull them, when the battery gives out, which it will. I like Japanese style saws, and a cheaper hardware store version is the Bear Saw. You can get lots of different blades for them. I use these for teaching kids carpentry. It's good to stop and critique your stance and technique once in a while and ask yourself if you are overextending or in a weird position, and if that is just life at the moment, or if the tool is affecting things, or it you could set things up differently. Smaller people need to use guile and intelligence to get things done rather than relying on brute physical strength--physics is our friend!
Try all tools thoroughly before you buy them. I have a Stihl weed whacker that is great, except when I need to bump that little button to advance the string. It turns out that you have to hit it square to the ground, and no matter how I adjust it, the angle is wrong for me and I can bump only one side. I either find something to stand up on when I bump it, preferably next to a solid thing to hit it on as well, or I have to stop and manually advance the string, which involves shutting off the engine, getting out the pliers (did I mention the span is too wide to take the little case off with my size hand?), pull out some more string, reassemble it, and start it up again. It makes me furious every time! But, I've discovered using a blade on it, so much of the problem is solved. Anyway, this is the machine everyone uses--it's really the standard one, but for shorter people, not so great. So, before you lay out real cash, find one to work with for a while first. And yes, I also use scythes, which are a fabulous tool, and are a good example of how having something sized to you personally is so important. Do lay out the cash for a custom snath--it's very much worth it.
Moving things like a sheet of plywood, where I am gripping it by just my fingertips when I reach across it, requires planning. There are special handles for this, which I have yet to try. I often screw a handhold onto sheet goods, or use a c clamp, if they have to go very far. I use a lot of blocks and lines and temporary cleats and braces to hold things up, where a taller person would just put them up and hold them while attaching. I recommend a book called 'Working Alone', by John Carroll, for a zillion helpful ideas for holding, lifting, and moving things. They apply to working when smaller too. I'm sure actual carpenters already know a lot of these tricks, but people like me who are constantly reinventing the world with the materials on hand can find some good ideas in it.
Mostly, don't give up! Just keep looking at and trying tools, or modifying them. All things are possible, you just have to find a way around obstacles and not close your mind to possibilities. If you focus how to get the task done, rather than getting stuck on using a particular method or tool, you take advantage of your brain, which is the most important tool you have.