More live rock is a good thing. You can try different foods but you gotta make sure she is eatin them. i watch mine like a hawk when I feed just to make sure she's eating.
If you cant say for 100% certainty that you actually see her eat prepared foods you will have to get some pods
for her. Or hope that you have enough in the tank to sustain her. You won't know for months though as they supposedly take a long while to starve. You will see the sunken belly and then you will know if you have enough.
Good luck, I hope you can get yours to eat prepared foods quickly. I;ve had a fair bit of success of getting mine to eat pods
. I shoot the tiniest prepared foods I can buy, like cyclopeez or plantkon right at her with the flow off. That way you can see if she actually eats any.