Since the most recent update, my household has adopted a cat and two of the sims had a science baby.
For the cat, only one of the 4 adult sims in the household got the "adopted" milestone - he was not the sim who initiated the adoption and wasn't on the lot at the time.
For the science baby, neither of the parents got the "had a baby" milestone.
I wish there was a way to add missing milestones since these issues seem to happen a lot.
