Michie, there is absolutely nothing wrong with being excused from jury duty, especially for someone in your situation. You're in a position where you simply
can't serve on a jury---you're a full-time care provider.
I only served once on jury duty, and it was years ago....I was unemployed at the time, so it was no big deal for me. It was an interesting experience, all in all, but nothing to write home to mother about. The one trial I sat through was a drug possession/B&E charge; we voted the guy guilty, as I recall. The next pool I was assigned to was an attempted murder charge---domestic abuse; the male had beaten the woman with an electric power saw and shattered her skull; they found brain matter in the woman's
throat. 
I wasn't picked for the trial on that one, and I was glad, because I definitely did not want to sit through that. Shortly thereafter, my time ran out, and that was that.
I was sent a letter a few years ago for jury duty, but I sent them an explanatory letter back with copies of my disability awards from the VA and Social Security; basically said that I was not physically or psychologically able to serve on a jury pool, and they did not call me back.
My dad was called once, when I was a kid. Being self-employed, it would have been a real financial hit for him to sit through a long trial. My mom asked what he was going to do, and he said, "Don't worry about it, I'll take care of it." He went to the courthouse on the assigned day, and within two hours, he was back. Mom asked what happened, and he grinned. Apparently the judge had reviewed the prospective pool, and when he came to Dad, asked about his background---Pacific veteran, certified craftsman, small business owner, etc., and then asked him, "Well, sir, do you think you can be a fair and impartial juror?", and Dad replied, "Judge, if the prisoner is a Jap, I say
hang him."
They excused him from jury duty.
