Hi,
Ah, welcome to life as the primary caregiver of a toddler / preschooler. You bring up several issues.
1) Carrying your child
There are a *ton* of baby carriers for carrying your baby or child on your body. When carrying an older baby or a toddler for a long time, your best bet is a back carrier. Front carry is really only for small babies. Hip carry is useful, but difficult to sustain for a long time. There are "frame" carriers which tend to be big and have lots of straps and buckles. There are also slings which are smaller, and can fit a wider range of ages. I like the idea of slings. The Maya wrap is one of the better known slings that adjust to a large range of child sizes. Another sling that has gotten good reviews is the Ergo Baby Carrier (
http://www.ergobabycarrier.com/). I have a Mei Tai, and I like it as it packs down to pratically nothing, yet can support a newborn up to a 40+ lb child (if the adult is strong enough). Keep in mind that there is a learning curve to wearing and adjusting any carrier, so if you want one, try it out and use it several times before you really need it.
2) Child's walking ability
You might be underestimating how much walking your child will be able to do in only a few years. A five year old can trek for quite a distance when used to such exercise, well-fed and hydrated, and properly motivated.
3) Caring for a child
A big step in helping *you* care for your child is teaching *her* how to care for herself. It starts with simple things like teaching her to dress herself, put on her own jacket, carry her own small bag, ask for food when she's hungry, entertain herself without electronics, follow urgent commands immediately (e.g. *stop*), try new foods, drink mostly water (vs. juice), and eventually to go potty by herself, etc. The less time you have to take care of these little essentials for her, the more time you have to take care of everything else, be it an ordinary day or an emergency situation.
4) Walking out vs. bugging in. vs. getting help
Realistically, if you have a small child, odds are that if an emergency happens, you would be better off bugging in or getting help versus walking out on your own.
I think that the single most important thing that you can do to be prepared with a small child is to cultivate the friendship of other local parents who share your views and have children the same age as your child. They will be able to provide you with advice and support that will be useful in emergencies as well as daily life.
-Kuovonne