These are my old ray pups, they are bigger than than 2". Theyre about the size of an average persons palm about 4", maybe 5".
Due to my own laziness and the fact that rays this small eat when lights are out, I feed them blackworms and pellets at night when lights were off. The pups are probaby about 2 months old and were captive bred and born in my tank. For the last 2 weeks I had them, they ate nothing but broken carnivore pellets. Today will be exactly one week that the OP has had them in his tank, so they are still a fairly new addition.
I personally think the female gave birth a week or two premature. The pups seemed a little small, but have grown very nicely and out of 6 pups, all 6 are still alive and are all in varying different waters.