Comparing the definitions of these two words as given by Merriam-Webster Dictionary online shows that excited suggests
a heightened state of energy, enthusiasm, eagerness, etc.
On the other hand, the meaning of nervous is
b : easily excited or irritated : jumpy
c : timid, apprehensive
nervous of strangers // a nervous smile
5 a : tending to produce nervousness or agitation : uneasy
a nervous situation // His face was twisted in nervous anticipation.
Thus the meaning of 'nervous' is somewhat related to the meaning of 'excited', but they are not synonyms.
In practice, I find (based on these definitions and my 34 years long experience with the English language) that 'excited' is most often used in a positive sense while 'nervous' is generally used in a negative sense, except when it connotes anticipatory apprehension, which need not always be negative, but can possibly be considered neutral or even positive, depending on the context, as in your example (paraphrase):
She was filled with nervous anticipation to think that she was soon to meet the famous actor, whom she adored.
In short you cannot substitute 'excited' for 'nervous' or vice versa except when both words are appropriate in the particular context and the substitution will not change the meaning.