En su vida se había sentido más nerviosa

[Stu]

En su vida se había sentido más nerviosa

It seems to me something like.
She never felt so nervous in her life.
But there is no negative word, so is that a reasonable interpretation.

[wrholt]

En su vida se había sentido más nerviosa

It seems to me something like.
She never felt so nervous in her life.
But there is no negative word, so is that a reasonable interpretation.

Yes. When this expression (and its variations with other possessive pronouns) comes before the verb in a clause, and especially when it starts the clause, it always negates the verb and it always means "never" or "never in his/her(your, my, etc.) life", unless the context of the clause makes that interpretation unlikely or impossible.

When it follows the verb, it is not automatically negative, and it has the natural meaning "in his/her(your, my, etc.) life".

[Stu]

Thank you interesting