I'm not able to get a reply sent to you via e-mail Craig. Not sure why it's not working.
The shrimp I raise are Macrobrachium rosenbergii.... they will not survive in water temperatures under 65 degrees F.. Not sure if that would work out for your MIL's pond, she would have such a short growing season.
Also I'm not sure what species are in her pond right now or if they would grow any larger. One option might be to find another market for them other than for human consumption.
You might want to check out the Mississippi State site MSUcares see if they will be of any help to you.
Sorry I can't be of more help Craig. I hope she finds a suitable alternative to her current venture.
Keep me posted on what you find out. :)