Answer
In the Name of Allah, Most Gracious, Most Merciful.
All praise and thanks are due to Allah, and peace and blessings be upon His Messenger.
In this fatwa:
There is no nothing wrong if a non-Muslim father serves food to his Muslim son or daughter.
Answering your question, Sheikh Mustafa Umar, President of California Islamic University, states:
There is no issue with any non-Muslim, especially a father, to serve food to a Muslim. What matters is whether the food is lawful or not.
If the food contains pork, for example, it would be forbidden, whether a Muslim or non-Muslim served it.
However, if it was a salad, for example, which contains no unlawful ingredients, it is permissible to eat, regardless of who served the food.
Almighty Allah knows best.