Is it allowed to feed the orphans and ask them to make a certain supplication for us? An example of this would be taking iftar to them and asking them to pray for us to have more children etc.
The Scholars say that it is not from the Sunnah to give charity and ask the one who received it to make dua (supplication) for you.
إنما نطعمكم لوجه الله لا نريد منكم جزاءً ولا شكورا
Meaning: “We feed you seeking Allah’s Countenance only. We wish for no reward, nor thanks from you.”
Surah Al-Insaan [76: 9]
The charity itself is a reason for earning Allah’s mercy and an answer to your supplication. The best supplication is when you feel the dire need for Allah’s response.