Samantha,
1900 Park Fare is a pretty good restaurant, but I would suggest that there are better options for your hubby's family as an introduction to character dining. Frankly, I am going to try it out again in October, to give it a fair shake, but I don't typically send people that way now, simply because I think there are better choices.
If it were me I would consider
Akershus. I have adored the food here since before it was even a character meal. You are getting the same kinds of characters, but probably will have more princesses to show for it.
And if you can introduce them to character dining at breakfast instead, I would even more strongly urge you to consider
Donald's Safari Breakfast at Tusker House in the Animal Kingdom park. That way they get Mickey and the gang in a fun, themed safari setting, and the food (despite being a buffet) is phenomenal.
Either one, in my estimation, would rate higher than
1900 Park Fare, though it would be a fine choice too.
So how is that wedding planning coming? I counted and this is question #21 between you and Allison!
Have a magical vacation!