This is a confusing thing to me too so I'm going to sit in and listen, though I don't think they should only be fed worms on a certain day. Unless you are just wondering how to split it up healthily. I usually give a hornworm once a day (depending on size of course) and feed either four or five roaches (depending on size) or 10 large crickets. My boy is a big eater right now only 7 months, and I've never tried silkworms... they are supposed to be more nutritious that hornworms but they are more trouble in my opinion. So I suppose it could be 3 silkworms that are like 2 inches for twelve pinheads... total guess XD though how old is your baby?
i do not have one yet i really want one but doing all my research first and my wife hates roaches so i cannot feed or breed them so trying to figure out all my feeding situation to avoid her being well you know annoying