Q: Is there max # of devices that can share Apple store purchases?

I have triplets and just recently bought another iPad to go along with two other iPads and two iPhones.  My kids apps are under my husband's Apple ID and this new iPad automatically went to my name since he already has one in his name.  Now the iPad won't sync to get my kids apps on it.  Is there a maximum # of devices Apple allows to share purchased apps, movies, songs. etc.?

Thanks