As a committed Muslim, there is nothing wrong in your attending the Thanksgiving party as long as no unlawful food such as pork or alcoholic drinks are served. On the other hand, you are not permitted to break your fast in order to share the occasion with your non-Muslim family during the daytime of Ramadan, as such sharing is not a legal excuse for you to break your fast. Being the only Muslim of the family, you should be keen to apply the Islamic teachings in order to be an exemplar for others.
Speaking about the Islamic ruling concerning attending Thanksgiving, the prominent Muslim scholar and Da`iyah Sheikh `Abdul-Khaleq Hasan Ash-Shareef, states the following:
“A Muslim is permitted to attend Thanksgiving as long as there are no illicit practices that contravene the Islamic teachings. A Muslim is not permitted to show any compromise against his faith. He is not permitted to attend such Thanksgiving party if the issue goes beyond a mere social event to include religious practices that are against Islamic teachings.
However, if that Thanksgiving event is no more than a social event where the members of the family attend and share lawful food (such as turkey), then there is nothing wrong in attending it.”
Moreover, the prominent Azharite scholar Sheikh `Abdul-Majeed Subh, adds:
“Attending Thanksgiving with your family is permitted as long as the occasion is no more than a courtesy in a social occasion and there are no prohibited foods or drinks that are served, such as pork or alcohol.
As a fasting Muslim, you are not permitted to break your fast to share the occasion with your family. If you did that and broke your fast, you would be a sinner in the eyes of Islam.
To the contrary, when you stick to the tenets of Islam, you will make a distinguished form of da`wah to non-Muslims, and they will be eager to know about your religion. By sticking to fasting, you will receive a great reward and at the same time you can apologize to the family, saying that breaking your fast to participate in such an occasion is against the tenets of your faith as a Muslim, and let your approach be gentle and make your apology even in an indirect way.”
Sheikh Ahmad Kutty, a senior lecturer and Islamic scholar at the Islamic Institute of Toronto, Ontario, Canada, concludes: “A Muslim who is eligible to fast is not allowed to break his fasting in order to share the occasion of Thanksgiving. It is not considered a valid excuse in Islam to break one’s fasting. Therefore, the person is only allowed to partake the meal with them during the night after iftar.”