C.G.
Babies at this age do not get their nutrition or calories from solid foods, it still comes from the breastmilk or formula so I definitely would not worry about it. The only purpose to giving solids at her age is to introduce her to textures and eating. The American Academy of Pediatrics recommends that breastfed babies start solids after six months of age so really she is barely above the age when she should be starting solids. Her stomach may still be feeling a little off so the foods may not be agreeing with her.
As for the crying at night, I am guessing it is related to not having the solids and/or her tummy being a little off after having rotavirus. I would not let her cry it out (I don't really agree with that in any case) but if she cries for 45 minutes, in my mind she is more likely to continue waking up every night than if she gets up for a few minutes, is calm, eats, and goes right back to sleep. Also, if she is truly hungry then crying it out will not really work- she will exhaust herself and fall asleep only to wake up hungry a little while later. Teething by itself also causes some babies to have sleeping problems. I would "baby" her for a bit- she has had a lot of disruption in her little life lately. She will go back to sleeping through the night for you soon. Good luck and I hope you all get some rest.