I am guessing the "split rock" is a lithops, they look 100% similar.

split rock is probably Pleiospilos nelii or bolusii
baby's toes is either Frithia or Fenestraria

Read Here for general cultural information on the mesembs, and find the info under each specific genus that you have as well. Educate yourself before you kill the plant and then write to this forum again wondering what happened.

Advice: absolutely positively NEVER EVER grow a cactus and the other mentioned plants in the same pot, guaranteed death to at least some of the plants. In terms of soil mix, read that article, it explains everything you need to know - I personally think that peat moss should NEVER be used for cactus and succulents but others will disagree, so you should experiment and expect losses before you figure out what works - we have all been there and we have all killed many of our own plants inadvertently, it is part of the gardening learning curve, just try not to let it bother you too much, but don't give up because the rewards are priceless.

I hope you find out which plants you have. Frithia and Fenestraria require completely different watering. Fenestraria leaves are completely smooth, Frithia leaves are covered in tiny bubbles. Three inches tall sounds like Fenestraria, that would be pretty huge for a Frithia.

I think you can potentially grow Fenestraria and Pleiospilos together although I don't. Both have very low water needs, will become dormant in very hot weather, and grow best in spring and autumn. The difference would be that Pleiospilos thrives on full sun and heat while Fenestraria doesn't like heat and prefers a little shade in summer. Both have large showy flowers, Pleiospilos usually orange on short stems, Fenestraria white or yellow, very occasionally orange, and on long stalks.

Ignore the tag. Bright light is poor advice, both plants will do poorly without direct sun although they might survive for a while. Fenestraria may flower in both spring and autumn if you grow it really well, but Pleiospilos will probably only flower in one or the other.

Only water when the soil is completely dry. Don't water thoroughly unless you have extremely fast draining soil, probably in a clay pot. Generally water lightly and fairly often, don't subject the plants to long droughts. Water especially lightly if the plants are dormant in summer. Once or twice a year when they are growing strongly, you can give them a soaking. If your Pleiospilos ever develops more than two pairs of leaves you are overwatering, cut back and aim for just a single pair of leaves by the middle of summer. If your Fenestraria's oldest leaves go mushy and die off, or any leaves develop splits, then you are overwatering.

I have some very small leaves on my baby toes that I consider to be new growth - they are emerging from the side of one of the original leaves.
I scarcely ever water this plant and being here in Texas where it is scorching hot - wouldn't dream of putting it in the sun. So why the new growth? The plant is losing some of it's lower leaves, but all in all it looks very healthy.
I changed pots today from a very small Lowe's pot to a 4 in pot - it was desert dry - should I water it a little?