Thank you very much for this question sir.
Heb.7.7 And without all contradiction the less is blessed of the better.
It's quite amazing you know. She needed the prophet. She wasn't doing him a favor. It's totally the other way round.
The reason?
Our blessings are always tied to our prophets. We need them to speak over our lives;
1Kgs.17.14 For thus saith the LORD God of Israel, The barrel of meal shall not waste, neither shall the cruse of oil fail, until the day that the LORD sendeth rain upon the earth.
This was the word of God, but it was Elijah who pronounced it. if she'd rejected him , she'd have missed out on her blessing entirely.
The first is unlimited supplies. It was only after she gave him her last meal, she had supplies that lasted throughout the famine.
The second was rescue from death. As a result of the prophet in the house, when the enemy attacked her son with sickness in 1 kings 17:17, he was revived after Elijah prayed.
Now you tell me who gained more or who was doing whom a favour?.