I have been wanting them for a while and have been researching them a little lately.I don't have them personally but from what I understand they do not like to be divided and will not bloom as soon if you do. Apparently they are one of the few things that prefer to be a little crowded so you MAY prefer to leave them as is rather than wait longer to see blooms. Maybe somebody with more experience could help you more. Good luck with them! -Ais.

Better late than never, maybe someone else with a similar question can benefit from my post.
Crinum lilies CAN be separated, but it'll be some work. We used to grow these all over when I lived in the Caribbean. Our gardener, a really talented guy, showed me how its done. You dig the whole flippin' thing up during its slow time since it doesn't really go dormant. We did this in January there. The mother bulb might be enormous. You can separate the large pups off with a big knife. The smaller ones with break off.
Replant the mother and pups in holes deep enough up to just below the base of the bulb. He tossed some well rotted manure in the bottom of the hole.
Our experience was that the first year after neither the mother nor the pups bloomed. The following year, they did and all set little new pups.
The whole process seemed pretty brutal, but they did fine afterwards.