Caroline does write to her parents but they don't make an appearance. On her trip to Paris she is accompanied by her pets; two dogs, two cats, and bear, leopard and lion cub. Its impossible to look at any illustration without counting to eight to find each of them and see what they are up to.
This crew didn't come together in the eighties though, because after I found this book I discovered the Petit Livre D'Argent, the French equivalent of Little Golden Books. At only €1.70 each they were mostly books originally published in the fifties. Here Caroline's pets made few appearances in stories of their own. Below, the fluffy kittens Pouf and Noiraud, have a snowy adventure and go on a camping trip.
In the centre, also by Probst is my sons favourite, "Si J'Etais" which roughly translates as, "What I would like to be when I grow up."
You really don't need French for these little books, the illustrations say it all, and they don't disappoint. Keep an eye out in the supermarket if you are ever in France.
P.s. Pierre Probst was a writer and cartoonist all his life and was hugely popular, mainly in his native France. He was born in 1913 and died in 2007. I've found some Caroline books in French on amazon and I know some were translated but so far haven't found any in English.