Looks like it to me, and yes, its cutting it close. But it does look like its ready to form a chrysalis. After which (about 10 days) it becomes a butterfly and will continue the migration south. In total, a generation from egg through adulthood lasts only 6-8 weeks (2-6 weeks as an adult) so the migration south is a few generations.

tj

Here is a link that might be useful: Monarchs

Yup, they're monarchs all right. I have perennial milkweed in my garden specifically for the caterpillars. I had to replenished the butterfly patch
with some new plants this spring because each year, they eat it down to the stalks, making it hard for the ascelepsias to come back in the spring.

Although the numbers wax and wane, I did notice that there were fewer caterpillars this year and they were late too.
However, mine have left already, having emerged a couple of weeks ago.

Every year I seem to find a few late stragglers who don't form their chrysalises until mid-late Sept. and eclose in early October... they seem to handle the temperatures okay despite the cool nights. I've read that as long as the temperatures are above 55F, monarchs can fly.

If your sister is worried about frost, she could always bring the caterpillars inside. There are a lot of knowledgeable people on the butterfly forum who raise caterpillars and could help answer her questions.

I found my last Monarch two days ago flopping about on the ground in the rose garden. It was dying. I scooped it up and it flew from my hands over to a rose bush and settled in there for a rest. Our temps dropped dramatically over night into the 40s. Poor thing won't make the migration South. :(

tsugajunkie- the monarch generation that migrates south lives for 8-9 months. It's the northern migration that takes a few generations to reach Canada.

I live just south of Minneapolis, and have released monarchs in October the past two years. If you want later monarchs, plant tropical milkweed. It's stays viable longer as a host/nectar plant AND it makes a good potted plant(so you can bring it in if there's an early cold snap). If you want more monarch-specific info, check out my facebook page, Tony

Here is a link that might be useful: Monarch Butterfly Garden