I want to find a romance novel about a concubine's daughter and a prince.

It wasn't that the daughter of a concubine was poisonous. He remembered that there was a part where the female protagonist seemed to have gone to offer incense or something. It rained especially heavily and washed away the bridge. Then, she took shelter in a farmer's house and met the male protagonist. The male protagonist led the guards to patrol the river bank. Then, the female protagonist personally cooked noodles for the male protagonist. There was also a scene where the male lead and the female lead were besieged in a mountain together. The male lead took the female lead to hide.