Well now...depending of course, on what the lady has, it *could* be worth that much! (I seriously doubt it tho)
The most expensive treadle to date, that I'm aware of sold at auction for 23,500 British pounds or $41,000.00. Here's the link for it...
http://www.sewalot.com/queen%20victoria.htm
This guy has a fasinating site with a lot of information on these old machines!