Lavender, in some lights and when compared to some colors, will look grey. That same paint color with different lighting or surroundings may look definitely lavender. She'll have to get a huge collection of chips, take them into her MB and start comparing them.

Start by finding some bedding, art, or fabrics that have the color scheme she wants ... it's easier to pick paint last in the decor process. Start with whatever is hardest, which is usually flooring or draperies

Here is a link that might be useful: All About Grey (and levender)

Check out Ellen Kennon's lilac, it's a very pretty color IMO.

My absolute favorite grey Lavendar color is Mercury Glass by Martha Stewart from the K-Mart and Sears line that she had. It was described as a warm grey w/ lavendar undertones.

The top row has the sample of Mercury Glass:

Our dining room is painted Benjamin Moore 1447 Amethyst Sky. Depending on the light is looks either more grey or more lavendar. I really like it. There are some weird reflections in the second shot, and the pictures were taken about a year apart, but you can see how the color changes in different light.

{{!gwi}}

{{!gwi}}

I just painted our master bedroom in Benjamin Moore "Dreamy Cloud" which is a very pale lavender, beautiful and fresh.

I'm planning to do the master bathroom in their Affinity (Aura) color, "Slip" which is a muted, dusty, very flattering lavender.

Both are beautiful.

Here is a link that might be useful: BM Slip

I just used BM Smoky Mist in my daughter's room. It is a beautiful lilac undertoned grey in the sunlight and plain grey in artificial light. Her room has eastern exposure.