I wondered if she was asking him what he wanted to eat and drink or if she was instructing him what

I would say, "I wondered if she was asking him what he wanted to eat and drink or if she was instructing him on what he could not order.", but your sentence isn't horrible. Maybe even "about" would be fine; my intuition's a little hazy on this.

Maybe after or  if she was recommending him what he should / should not order seems  not horrible? 

In fact the question is not clear. Should we control the usage of indirect speech? It is grammatically correct. Should we control the meaning of the sentence? Anna and I say there is a problem but actually we do not know what you wanted to say.