Breakthrough Chickenpox infection... what to expect?

Sigh... Kivi has chickenpox. She was vaccinated around her first
birthday for varicella, but she, and at least one other child (also
vaccinated) at her daycare have chickenpox.

It *does* appear to be a light case of it. Both the doctor, and the
nurse at the daycare said that since it's a breakthrough case, that
she might not even get the crusts. She hasn't had a fever at all,
though she was VERY cranky and unhappy the week prior to getting
spots. (She had been crying "I want my mommy" on and off all day
while at daycare, and was cranky in the evenings, and this is the
child who the weekend previously had gotten angry because she didn't
*get* to go to daycare because it was the weekend - and everyone, from
the janitor to the center's nurse had said "what's up with Kivi, she's
usually so happy!"). She *had* told us a couple of times that she was
sick, but when we asked what was wrong, she told us her leg was sick.
At 2.5, she is pretty verbal, but not verbal enough to tell us what
was wrong. We're getting ready to move, and we are are packing things
away as well as remodeling to get the house ready to sell, so we
thought that was upsetting her. In the end, I suspect it's a
combination of both.

We noticed spots on Saturday evening, and by Sunday, it was starting
to look like chicken pox (blisters), with more and more developing.
She has them primarily on her chest and belly, a few on her back and
shoulder blades, and some on the backs of her thighs. The sores are
smaller than my stepsons or brothers, and I'm not sure they'll crust
over. They don't look like it, anyway, not yet. But it's still early
in the illness. Chris took her to daycare this morning (Monday) --we
weren't sure it was chicken pox, since we thought it was unlikely to
actually be chickenpox since she had been vaccinated, and hadn't
appeared ill, and only 1-5% actually do get it after vaccination--but
at my suggestion stopped in the nurses office first, and had the nurse
look at her, and she imediately sent Kivi home.

Either way, I was wondering what to expect with a breakthrough
infection? My stepson had chickenpox, and I was around when my little
brothers had it, so I know what it's normally like. What should I
expect for a kid who had the vaccination already, and now has the
disease? Is it true that she's not likely to get the crusts? She's
had no fever whatsoever in the last week (and had a temp of 97.1
armpit at the doctor's office). How long did it last? What are your
experiences?

Cathy Weeks
Mommy to Kivi Alexis 12/01