Hello Arborbluffgirl,
I have only started growing Lewisia cotyledon (hybrids) during this past year. I am in coastal central California
just above the major bend on the coast headed to Santa Barbara. I have my plants hanging on my greenhouse-though one is just sitting on a shelf. all in clay pots. they get as much direct sun as I can give them. I would guess from
10am to 3pm but I have not really tracked the time on this.
It is hard to believe but they are starting into their 3rd flowering this year! I think the trick with these plants is that they need the shift in temperatures and in moisture to help initiate flowering spikes (this is only my surmisal).
I let the soil the plant is growing in get fairly dry and I watch the leaves to see if they get lax or winkled then I give them a good squirting with the pressure sprayer. The nighttime temperatures are running around high 40s with daytimes into the high 70s though the plants may heat up
on their leaves into the 80s. The sun can be very hot when
the wind is not blowing.
So I think that you will need to relocate them to the sunniest spot possible or do some trimming to let more sun
get to them. Water wise a little drought will not kill them.
The nicest species, L. redivva, actually goes dormant dying back to the ground and so I would suspect that the other species are capable of doing the same though probably for less of a period of time than L. redivva.

Thanks for the response terrestrial man. I am going to have to relocate them to a sunnier spot.