Based on the Flotrack Q&A with Jordan Hasay, it looks like she is running 100 miles a week just 2-3 weeks out from Boston:
For those who don't want to click, this is the question:
How many miles per week are you currently running? How long is your longest run?
I've gone 25 miles a few times now with a one mile cool down. So technically I've gone a marathon! I've done quite a few 20 milers as well. I'm at about 100 miles.