I adopted a pregnant kitty (Princess Chelsea Pearl) and those babies just loved Royal Canin Baby Kitten food. It's little tiny kibble, looks kinda like Grape-Nuts cereal. I think they started trying it at around 3 1/2 weeks. I mixed it with KMR - it really looked like cereal then! Plus Chelsea loved it too - great stuff for a nursing mama cat..... If the momcat is bringing bugs to Angel I would say it would be safe to offer either wet kitten food or the baby kibble mixed with KMR.
And I have to say.....every day the first thing I do is go to Cat of the Day and see how Angel and Momcat are doing!