Wow, it's a Sunday and I have a little time so here's an essay!
I shoot with both Canon & Nikon systems, they both indeed do a grand job.
Definitely spend the majority of your budget on a good lens. A high grade lens on a budget body can and will produce very fine results, a bad lens on a high grade body produces sub standard results that you will most likely grow out of quickly.
The biggest hurdle, at least on the early stages is that you have varied needs in terms of focal ranges with lenses, you mentioned kids portraits, wildlife and macro for instance.
Each category can require different ranges, all the below info is purely for example and from my opinion. You'll find that everyone does things a little differently.
For portraits, prime lenses such as an 85mm, a 50mm or 105mm are great choices but you may want the versatility of a zoom lens such as a 24-70mm or a 24-105mm. All these aren't really going to assist greatly with macro or wildlife photography.
Wildlife photography can warrant something like a 70-200mm, 100-400mm in the zoom lens ranges and anything from 200mm, 300mm, 400, 500+ primes.
A 70-200mm can and is used for portraits too but not so much the longer telephoto kinds as you'd be yelling instructions to your subject.
There are quite a few talented photographers out there that use 300mm f\2.8 lenses for macro but 300mm lenses are very

expensive.
Macro can be done expensively with dedicated macro lenses ranging from 60mm, 105mm, 150mm and 180mm but also inexpensively with a 50mm prime lens and a reverse ring, a more difficult set up for a beginner but much, much cheaper. A Nikon reverse ring for example is around £20 and below.
We have a member by the name of
Alby, check him out for macro also check this
guy out, visit his blog and go to the information section for details.
I used to use a Sigma 150mm f\2.8 macro lens for the occasional portrait despite it being a touch long but a dedicated macro lens is really just that - a macro lens- for small details and the like. I found that shooting far away subjects with the 150mm macro, such as landscapes, the image quality was very unimpressive.
As you can see, these categories are quite varied and it maybe more beneficial to start with a good standard zoom, say 24-70mm perhaps, either that or a 50mm prime lens.
There are plenty of arguments out there on the prime lenses being better than zooms for consistent quality. I think I would have to agree but I rely heavily on a 24-70mm zoom for many of my portrait jobs.
Being as you mentioned that you have small hands, I would seriously advise to go and handle both Canon and Nikon camera bodies before making an investment.
Both systems have very different ergonomics, I describe the basic differences like this, Canon camera's have a combination of buttons and lots of menu's for the different controls. Nikon systems have a button for nearly everything.
Both are fantastic systems but the point really is getting the system to suit your needs best.
Concentrate on the lenses more than the body.
Good lenses will stay in your inventory while bodies have a life cycle.
Hope this helps some.
T