Another deity might offer blessings to produce normal offspring from a marriage with halflings, but Jinnari and Hiragya are very defensive of their charges. They mean well, but they have the minds of children; being overzealous, cantankerous, and seeing the world in black and white. The halfling curse is dominant because they themselves have yet to be convinced that there is any reason for an uncursed to be attracted to a halfling beyond pedo/hebephilia. They'll keep the children looked after because all children are their charges and try to direct them to their temples if neither parent will accept; but you'll still get the curse of your offspring with that halfling always being more halflings. And no, halflings can't grow up without proper application of divinia.