What is the ruling of the Sharia regarding a daughter who slapped her father on his face to stop him from caressing her and attempting to bite her "like a husband [would his] wife"? Is she considered sinful towards him, and must she seek his forgiveness after five years of her marriage?

The woman's suspicion of her father may be a whisper from Satan. The father should not fondle his adult daughter in such a manner, and the daughter should not enable him. However, it is not permissible for her to curse him or slap him; this is a forbidden act of disobedience to parents. Allah the Almighty says: "And We have enjoined upon man [care] for his parents. His mother carried him through weakness upon weakness, and his weaning is in two years. Be grateful to Me and to your parents; to Me is the [final] destination. But if they endeavor to make you associate with Me that of which you have no knowledge, do not obey them but accompany them in [this] world with appropriate kindness and follow the way of those who turn back to Me [in repentance]. Then to Me will be your return, and I will inform you about what you used to do." She must repent to Allah by feeling remorse and resolving not to repeat it, and by increasing good deeds and supplicating for her father, without informing anyone about this matter.