Como dizer "Estar interessado em" em inglês

Perdão, eu achava que pudesse usar as duas estruturas para o mesmo contexto, agora percebi que cada caso é uma estrutura diferente.

Corrigindo:

Be interested + in + verbo + ing
She is interested in becoming an engineer (ela está interessada em ser uma engenheira)

Exemplo adequado para a estrutura:
Be interested + to + verbo infinitivo
She was interested to know if... (ela estava interessada em saber se...)

I thank you for correcting me.

It is odd about our language isn't it that you can say
She is interested to know....
but not she is interested to become. Possibly because the verb become is a linking verb that takes a predicate nominative and to know would be a transitive verb that would take a direct object.
Or possibly after in you must use a gerund as the object of the preposition. I am glad I learned English as my native language not as a 2nd language! However Portuguese is very difficult to learn also.