I am so sorry to hear about your MIL.

Alpaca is also a soft, hypo-allergenic yarn. It is lightweight as well. I farm alpacas and so I might be a little biased, but I do know for a fact that the diameter of alpaca hairs is finer than that of cashmere, and has better tensile strength, is easier to cultivate (i.e. does not have to be imported from the dustbowls of China) and is readily available in the U.S. (just google a local alpaca farmer near you.)