You need to be atleast level 45 to share exp with your wife.
Level 45 is the minimum level what makes marriage avaible.
So if you aren't that level, you simply can't share exp.. I checked scripts myself before about this, it's all in it.
Then again, your wife also needs to be 70 (Or w/e the level is to adopt) to party share with your Child. Same reason as above.
(This counts for eAthena, I'm not sure about Aegis)
Sorry if someone already answered a reply like this.
I haven't read anytjhing above. :x /lazy