Silly question, here...but, when you added the ACV, you did make sure that you had shaken it really good so that the Mother was not all settled on the bottom, right? If you didn't, you can shake it up and add it, now. Or, to avoid adding more ACV that some chickens find offensive in large doses (not mine, the little pigs) you can toss a tablespoon of active baking yeast into the mix.
Ok Yeast worked beautifully! Thank so much! I put it out for them this morning for the first time - so I put about 1/4 cup of their regular feed on top to disguise it - they ate like pigs....and ate AROUND the regular feed! Some of these ladies are 4 years old!! I never dreamed they would take to it like that! So excited! Ready to start my 4 week silkie chicks on it!