Can a Muslim girl get married with a Christian boy?

No, she can't unless the Christian boy converts to Islam based on free will and good faith and not only to legible to marry the Muslim girl.

Per Islam teachings and rules:

• A Muslim boy can marry a girl/woman who is Muslim or Christian or Jewish and they can keep their original thoughts. However,
• a Muslim girl can not marry a Christian or Jewish boy. She is allowed to get married with only a Muslim man.

In Islam practice, the husband prime responsibility is to cover the family expenses even if his wife works and even if she is earning more money than the husband. In addition, Muslims have faith in the holy books (including Torah and Bible), and in both religions of Judaism and Christianity, and all prophets (including Abraham, Moses, and Jesus) while Jews and Christians do not have faith in Islam, in Quran, and in prophet Mohamed.

So, it is logic if husband is Muslim to accept for his Christian or Jewish wife to practice her ritual worships, social activities, and clothing according to her Christian or Jewish religion. However, if the husband is Christian or Jewish he may not accept his Muslim wife to practice her ritual worships, social activities, and clothing according to her Islam religion.

That is why a Muslim man can marry a Christian or Jewish girl/woman while a Muslim girl can not marry a Christian or Jewish man.

Some others have the view point that any person of any faith can marry anyone they want and that love conquers all, even religion. However, this is true only if you are not committed to a religion with God or not believing in God at all. If you are committed with God through any religion, what so ever, you have to fulfill this commitment. This is in analogy to one committed with an employer through a work contract (despite the difference between commitment in contract with God, the Creator, and commitment in contract with an employer, creature). Does falling in love with someone entitle you not to go for work or not to fulfill your work commitment? The same answer applies to your commitment with God when you fall in love and thinking of marriage. On the other hand, of course you have full right and full choice to select either to fulfill religion commitment or to abandon the religion you committed to and throw it behind. However, choice is responsibility. You should be aware that your choice defines the consequences that you get in front of God on the Resurrection Day. Either one goes to God Paradise or one be Pushed in Hell fire.