Thanks for the additional information. You did state that she is developmentally delayed. As a result, her fraps might be relatively normal for a younger dog like a 4 month old dog. Younger pups frequently act in the manners you describe so her behavior might be a continuation of her developmental issues.
I think boarding training isn't a bad idea, but you need to know that the dog will need extensive training with you as the handler. I always suggest you train at least 30 minutes a day (two 15 minute sessions). Dogs learn to respect the person doing the training and see them as the boss. While another trainer can teach the actual commands, you also need to teach the dog to see you as the boss and that is where doing the training yourself comes in. I would start making your dog work via the Nothing in life is free program (NILF). It is outlined below.
I strongly suggest that you do more extensive exercise with her. I'd have her growth plates checked and if they are closed or almost closed, up her exercise to some fast paced walks. Don't let her sniff and socialize. If that isn't possible due to your health then you might consider a treadmill. Tire her out 2-3 times a day with a good fast paced walk or run on the treadmill.
It sounds like your crate is good but keep all the extra stuff out of the crate. No blankets or pillows or other things she can destroy. Put her in there for meals or if you have a yard, feed her in the fenced yard and ignore the running around. The more attention she gets for it, the more they will display it. Try to have her in a place where it won't matter if she displays frap behavior. Most dogs will outgrow the behavior if you don't reinforce it with attention. I suspect her developmental delays are helping contribute to her still displaying it this late more so than reinforcement but have to mention it.
You might also find her a playmate of similar size and preferably a neutered male. This will help her get out excess energy through playing with another similar sized dog on a regular. Another dog might also help her learn to control the fraps as well.
You might try a DAP collar as well. Normally it is for anxiety, but it might help keep her calm and it is not medication but a pheromone so shouldn't affect her bowels or interfere with other medications either. Give these suggestions a try and see if you see improvements.
I hope this information is helpful to you. If you would like any additional information or have more questions please don’t hesitate to press the reply to expert or continue conversation button so I can address any issues you still have . If you do find this helpful, please take this opportunity to rate my answer.