Tea' just had her pups on Sunday and the day before, her temp dropped from 100.5 to 99.3...
She was on day 60 also, started the digging thing, wouldn't eat..and sure enough within a few hours (she didn't want her box at first, sat next to me on the bed for goodness sakes) and started these amazingly strong contractions...this was at 10 in the morning (was expecting a night birth, don't know why) and the first puppy came within ten minutes of this starting!
Good luck to you and your mama..let us know how she is progressing
Debbie