Yes you sure do have a lot to think about! With the earliest possible due date being the 25th., I would be tempted to not give the Dex tomorrow. If she is progressing on her own, (discharge, dilation, ect.)and comfortable, maybe give her a little more time. It is only the 20th.. 5 days early, not so bad. 26 days early, not so good. You are definitely walking a fine line by waiting, and her having enough strength to give birth, or inducing, and having the calf too early. My thoughts are, you are more likely to be able to save the calf, than to save her. So let the calf mature and be on alert for signs that it is ready. (just as you are.) If no immediate danger........