buy some spelling game software... that should be a fun and learning experience... learning should be fun or else all its going to do is frustrate her... 

when she gets a little better with words then dump her onto books... no point of her reading teen books if she can't recognize enough words for her to appreciate the book... she's 13 so children books may discourage or insult her... also try buying her some teen magazines, girls love those...

You are probably correct when you say that "no one (two words) has spent any time teaching her at home.  Don't be too disappointed though!  She is on the "right track".  You said, your niece spells "stomach" as "stumak"  and "bark as "bak".  She is spelling her words phonically.That's a good start and is not discouraged in creative writing.  Many teachers don't want to discourage creative writing by pointing out too many spelling mistakes. (Too many red marks on the child's paper).   However, since your niece is 13, some correction needs to be made.  Care must be taken that the child is not discouraged from reading and writing.  As her guardian, you will have to spend some quality time with her.  Read with her every day.  Don't just "tell her to read". Sit down with her and read something that is interesting to her.  For instance, Try teaching her to do baking.  Then she will need to read the receipt.  Ask her to find a good receipt. There are lots of ways to stimulate the child's reading/writing skills without calling too much attention to her errors. "Encouragement" is the word.

GOOD LUCK!

My daughter and I have been using Spelling Power now for 2+ years.

She learned to read so rapidly that we pretty much skipped phonics

instruction. She is a fabulous reader, but I was concerned about her

spelling. I bought Spelling Power at the homeschool convention, and it took

me a long, long time to read it. To be honest I was intimidated by the

huge SIZE of the book and the density of the instructions.

I started using it around December '04, and boy is it great!!

The instructions, I realize now, are just detailed to the 'nth'

degree. The program isn't as complicated as you might think at first

from looking at the opening chapters of how to !! It works really

well, takes about 15 minutes a session, and let me tell you, it makes

sense! The words are connected to one another by a phonics rule, and

you run thru them (as many as you reasonably can, not neccessarily the

whole list). In my days in school, spelling words always seemed to be

very randomly thrown together, and if you got them all right in the

pretest on Monday, you still had to take the stinkin' test on Friday.

How annoying, and what a waste of time. If I know how to spell it,

wouldn't my time be better spent learning something I don't know ??

Any words the child gets wrong are studied and you retest the next

session just on those spelled incorrectly. All of the rest are

'horray!" and you move on. The word is 'corrected' immediately after

it is spelled by the child, so if there was any doubt in their mind

how to spell it they know right off.

She really took to it and her spelling is terrific, around the

9th grade 'level' (according to the book) at age 8. Now if only

her handwriting would follow suit... :)

Solid thumbs up for this program. Oh, one final note, it isn't cheap,

$60, but it has words that will last you many, many years, probably

right thru high school and beyond. The difficulty goes way beyond what

I am comfortable spelling off the cuff!

To sum up, I love the following about it:

1. The child is placed according to his abilities in response to a two

step screening test. (not based on age or other arbitrary thing)

2. The words are grouped according to a spelling rule, instead of

being based around a topic. This helps reinforce the spelling rule in

the child's mind.

3. The child only studies words that she misspells, not the ones she

gets right (no wasting time) - yet words are repeated throughout, so

if a kid gets lucky and spells a word right, they'll see it again!!

It looks intimidating because the first 80 or so pages are just small

print details of how the author came up with the program and how to

administer it. I was very overwhelmed by that at first, but once I

finally looked at it, I realized it is just like a regular spelling

test (except for the above positive points). So don't be fooled or

intimidated, the author just likes her subject and wants to discuss

her theories of how best to learn spelling in detail. You don't really

have to read it all :)

Finally, the cost of the book is around $60 although I found mine used

for $25. The program would be good to cover grades 3-12, so consider

it money well spent.

Spelling Power

Well, my first instinct is to say - teach her how to pronounce things differently! My spelling is impeccable because I sound the words out in my head. From the sample spellings you gave sounds like her pronunciation is at the root of the problem here - montons? gil? Perhaps you live in a strongly-accented region... If you could teach her to say "mountaynes," etc, even though it's not really proper, it would help her with her spelling till she got it right. 

The other thing that really helps spelling is reading. Have her read read read - find out what's interesting to her and get TONS of books on the subject. The more we read, the more we soak up information about how to spell, construct sentences, write - it's an imitation process, just as we learned how to speak when we were very little.

Spelling can be taught in a number of different ways. The most obvious is to expose the child to more text with lots of vocabulary, that way they will see the words more often. A fun way is to play word games and double check the words in a dictionary. Another idea is to have the child make her own dictionary. Get her a notebook or something that she'll like to use, starting on one side she can put school words in it, like words that she needs to know how to spell and on the other end of the book she can put life words and any word that she reads in magazines or sees on posters can be written in to the life words. Since these words have more meaningful attachements, she should be able to pull the dictionary out when needed and write the words correctly