It is quite true that you are married into family of your spouse, but you are not married to that family. The spiritual feelings also say that husband and wife become one soul after marriage.
So, try to maintain always harmonious relations with your spouse. But it happens sometimes that the in laws (her parents) indulge in much interference of your married life and they try to influence on each and every matter related to you. This is the time when feel demoralized and made to think to whom you are married, her or her family?
It is always suggested that you avoid conflict. Don