I am tossed about adding another pup when it comes to your time already being limited with one pup. You could end up lucky with 2 pups who entertain each other and calm each other... or you could end up with 2 pups who are both an anxiety riddled mess!
You can buy a plug in at the petstore.
Comfort Zone® Plug-In for Dogs | DrsFosterSmith.com
It does seem to be helping my little guy. I have 2 boys, they are brothers that I got from the same liter at the same time. They do offer each other a measure of comfort, but my Dexter has major anxiety and has done quite a bit of damage. About a month ago, he ate through a wooden baby gate I used to pen him in about 3 days, he just tore it apart until he made a hole to get out. I replaced with a heavy plastic gate and got this plug in thing. He does seem calmer with it though.
Is it possible you can take your girl with you to the fields for the kids games? I have 2 step sons that were in 3 different bball teams and I took my boys to the games. They loved it and it was an easy way to get time with them and be there for the kids too. Fitting one dog into a busy lifestyle is easier than fitting 2, so I would try taking her with you whenever you can before getting another pup and possibly getting twice the problem.