Congratulations on your two loveable Dachshunds DJ & Jade. They sound adorable and still very much in their puppy hood. It sounds like these two girls have taken over the household and you and Jaci are getting very well trained. Have you taken them to obedience classes yet? This would be a very good place to start training and getting them use to you and Jaci being leaders of the pack.
For first time Dachshund guardians I highly recommend the book “Dachshund for Dummies”. It is a very informative book and will answer most of your questions.
I don’t like the idea of muzzling dogs especially puppies, you need to train them not to bark. After all they are puppies and need to be taught rules, boundaries and limitations. I would suggest using a small spray bottle filled with water and a touch of vinegar. When they bark spray them and tell them NO BARK! There is also a Citronella Anti Bark Collar that some use and have been pleased with the results.
Rolling in the dirt is not the sign of a mating behavior. All dogs love to roll in dirt and sometimes unpleasant things. You just have to keep an eye on them and get them interested in something else, a toy or chasing a ball.
The first sign of the girls going into heat will be a swollen vulva and after a few days the bleeding will start. This heat cycle is 21 days. I would highly recommend you have your girls spayed as soon as possible, do not let them go into heat. Spaying will lessen the chance of mammary cancer in later years. At the present time there is a serious issue of pet overpopulation and allowing your dogs to have litters you are adding to the problem.
I hope I have answered your questions. Get your girls spayed and into obedience class soon as possible. Good Luck!