DD is 3.2. Most of her Dutch DVDs have Dutch / French options. Well last week I wasn't paying attention and put the French version on instead of the Dutch and buggered off upstairs to change the beds.
When I came back down 15 or 20 minutes later, I found Spot chattering away in French and a perfectly happy DD 
Dutch is the societal language here, DPs language too, so no lack of input. Her Dutch is good, better than her English.
DD now keeps demanding to have the French option. Is there any harm in it? Neither DP or I speak French to any standard.