Mountain Biking - SIDI Shoe Sizing - confused

I am trying to mailorder a pair of SIDIs (mountain) for my wife.

She wears an american size 6 shoe. According to the chart on the SIDI website
that would be a 36.5 metric. (thats gonna be way too small - see below)

so far tried:
SIDI Dominator 4 size 39 - way too big (in width and length) - I dont think this was a womens
specific model

SIDI Lightning Womens size 38 - too small (in length) - this was a mistake anyway as it is a road shoe

Any women using SIDI s and can help with the sizing?

My LBS has a very small selection of shoes so no help there.

I am trying to mailorder a pair of SIDIs (mountain) for my wife.

She wears an american size 6 shoe. According to the chart on the SIDI website
that would be a 36.5 metric. (thats gonna be way too small - see below)

so far tried:
SIDI Dominator 4 size 39 - way too big (in width and length) - I dont think this was a womens
specific model

SIDI Lightning Womens size 38 - too small (in length) - this was a mistake anyway as it is a road shoe

Any women using SIDI s and can help with the sizing?

My LBS has a very small selection of shoes so no help there.

I've cycled for over 30 years. There are a number of items I would buy online, but cycling shoes would not be one of them. Gotta try them on. No two pair of feet are the same. If possible, I'd plan a road trip in the family car to the nearest bike shop of significant size after first calling them and ascertaining they have a range of sizes for her to try, preferably in more than one brand. They do not necessarily have to be women specific as the main difference between a man's and women's cycling shoe is a narrower heel area. The important thing is find a shoe that fits, be it women's specific or otherwise .When you say she wears an American size 6, is this women's sizing or men's? There's about a 1 1/2 size difference between men's and women's sizing. A women's size 6 would be a men's 4 1/2 and a men's size 6 would be a women's 7 1/2.

I wear size 7Men's shoe Size 9Women's(little bigger than men's size 7) running shoes. I have bought cycling shoes in 40, SIDI and Diadora, and also Shimano and Nashbar brand shoes. They all fits nicely, and all through mail-orders. I believe the chart you found on the SIDI web site is wrong. Women's size 6 can't be 39(Possibly mistaken as men's size 6). From my experience, Italian brand shoes seem to be pretty consistent to the size they describe. If you worry about getting wrong size shoes through mail-order, go to any store that sells Europian sizing shoes and find the size that fits. Once you do that, you can be pretty confident buying them online.

I forgot to tell you that Shimano shoes I described above are size 39. They are road cycling shoes and I bought one size smaller intentionally for tighter fit. I got pretty much what I expected.

You're deffinitly going to want to have her try on a pair before she buys them. When I needed to find a pair of shoes in a size 14-1/2, I went to Supergo, I tried on a few pairs of Dominators (They didn't carry Genius in that size) until I found my size (Which I believe was off from what the Sidi chat listed as my size, this is why it's important to try them on first), then I went to my LBS and had them order a pair of Genius 4's for me. They fit perfectly, the sizing of Dominator and Genius is the exact same.