Depends a lot on how much she enjoys texture. I personally like my dildos to be smooth or only lightly textured for the most part, so I'd go with the Silk.
I've tried the Charmer, and didn't enjoy it at all.
It's also a fair amount larger than the Silk, even though Eden lists it as being only 1/8" larger in diameter. According to Tantus's site, it's roughly 1/2" larger.
The Compact looks interesting, though I've never tried it.