Should I repot these?
They are in 4" pots. They have been in them for quite some time now and they don't seem to be growing much.
Shhh, Will might hear you!
Now just wait...these plants will probably be exceptions to the three-day watering rule and I'll have egg on my face - again.
BTW Phoenix, what are those plants? The leaves look somewhat similar to a Cereus but different growth habit.
Phoenix,
Larger pots don't promote growth any more than larger shoes will make kids grow faster.
Your birds nest ferns need brighter light for longer periods through the day. Right on a north or east windowsill would be good. Once the roots fill up the pots, then more energy will be put into growing more foliage.
In case I wasn't clear, don't repot.