1) Coming Up With A Character Concept and Then Subtracting Most of the Age is NOT INTERESTING.
Having a cleric is fair enough. They may or may not be interesting.
Having a four year old cleric IS NOT INTERESTING.
Four year old goddesses are also NOT INTERESTING.
neither are four year old slave girls, four year old psionicists, or the majority of four year old anything for that matter.

1 a) How To Play An Interesting Kid
The most interesting children I have EVER seen played have been simply that: kids. Perhaps kids who've slipped from their mothers watchful eye for awhile, perhaps kids who've 'run away', perhaps they are eight year old clerics escaped from the priests awhile... but the thing is, whatever the reason they're there, THAT IS NOT THE CENTRAL THEME OF THEIR EXISTANCE. They're just kids, reacting the way a kid would to dragons and angels and such minor things as interesting pebbles, or butterflies, or grassy slopes.

Note also: all kids of all ages do not have a uniform vocabulary, appearance, or need for affection.

An eight year old is pretty mobile on his or her feet.
A four year old babbles incoherantly a lot.
A five year old should be mostly legible.
The correct language alterations do not simply involve dropping every second sound in every word no matter what the age. Check it out, do your research, and type it right.

THIS IS NOT INTERESTING:
Anthea, 8 year old High Priestess:
*she walks in and looks around. She looks neglected and lonely and put upon and is desperately trying to get some attention*

THIS IS MORE INTERESTING:
Anthea:
*she poked her head around the corner, eyes blinking hugely. Cool! What was this? It was cool, anyway. And big, which was also cool. She sidled in with the guilt-ridden pleasure that seemed doubly as good as the normal sort, knowing she shouldn't be here but oh, so pleased that she was. She couldn't have been more than seven or eight, and she displayed every inch the open curiosity of a truant kid that age*

Note the difference. I mean, maybe Anthea is a High Priestess... maybe in the next post you mention some gown that's too big for her and the way she seems so clearly to have run away from some responsibility- but Anthea is still A KID, if that's the way you've created her.