Tatiana was not forcibly married. Tatiana heard from her semi-fantastic Ideal that they are not needed and married herself.

You have some misguided ideas about the morals and the life of the nobles in the Pushkin era. When marrying her daughter, her opinion was not much more interested than today, the breeder is interested in the opinion of the cat when it is sold. A person is good, responsible, will not hurt - this is the main thing. And then it will fall in love. Again, Eugene was not just so excited to Tatiana: she is now married, but the place of the lover is vacant. He did not want to get married (until death separates), but to spend some time with a young, beautiful, but naive lady - it is.