I've noticed this timer issue before, and mentioned it elsewhere. It only seems to affect the original nursing mom from the raft.
My Pg female is in fact one of the 8 originals. Same goes for my 13 year old, whom, I think, will never grow-up. I am keeping an hourly text log as this is really beginning to get under my skin. At 21:20 my Pg lady had 114 min left, it's now 22:30 and there's still 114 min left.