What you can do really depends on what classes are in the party and what level everyone is as to what you can do beyond use a heal check. There are certainly no rules against your desperate prayer; that would be up to your GM to decide, but I will warn you: If it works, you may not like what you have to do in return for this boon. If your GM is bloody-minded, like me, that kind of prayer really does open up the realm of possibilities for "What terrible things can I have befall the party next?" Just be careful about how you phrase your request.
You could try talking with fellow party members. Does anyone have the Healing domain? Do you have a cleric with spells like Stabilize? Potions, scrolls or a wand of healing would also work to keep your little NPC friend from dying. See if you can make it a party effort if it's that important.
