Sigh. My sis in law and I had a convo about taking MIL's keys away. MIL had had her 90th b'day and was still pretty spry, but there were some indications it was time .... But before we could actually do it, she pulled out in front of a semi.She knows and we called her and explained and ask her to call us when/if he made it home. She did and thanks us profusely.
I will always wish we had acted sooner.
