Nick,
As Max (edwmax) mentioned, and if you can, transplant them using coarse sand!.....I always used coarse sand and lots of perlite mix as medium for Nanas in pots!....Trust me works like a charm!....
Also, as the mother/main plant, keep the babies/nubs/pups in a dry location after transplanting them!....Initially, I always add water when transplanting Nanas to take out any air pockets traps within the transplanting medium.....Then I will add water every 6 to 7 days until I see new roots (rooting) and/or new leaves.....Then I will water normally every 2 to 3 days!....