Nothing against the OP and I agree it sucks when your employer makes rules for trivial reasons, but they are paying you for your time. If you don't like their rules, quit and find another job with a more relaxed work environment. I used to work in a very strict place where they treated professional employees like children and I hated it. I make less money now but I'm in a much more relaxed environment and I would never go back.
It's scary how much I've seen the "entitlement mentality" entering the workplace lately, from Glass and smartwatches to time off and schedules. Lots of people expect employers to cater to their wishes and then want higher wages too. A good employer will have consideration for their employees and treat them well, if they don't just move on and don't expect them to make exceptions for you. Unfortunately with the current state of the job market here in the US this is easier said than done which is why a lot of people have to stick with crappy jobs...
On the other hand many workers are required to receive notifications from work when they are at home, so why shouldn't they be entitled to receive notifications from home while they are at work? Employers in the U.S. are notorious for demanding more from employees than 35 or 40 hours a week. Unpaid overtime is rampant in the U.S. I have been in the IT industry since the mid 1990s and I have always been expected to take my work home with me. If an emergency comes up, I have to drop what I'm doing and deal with it. Fortunately most of my employers have been willing to say that it's okay for me to take some comp-time if I end up working a lot outside of normal hours, but that is a small consolation if I have to cancel an outing with the kids or leave in the middle of a movie. Still, I have been lucky because aside from emergencies and the occasional scheduled after-hours maintenance most of my employers haven't expected more than 40 hours a week out of me on a normal week. On the other hand they have gotten more than 40 hours a week out of me on many occasions because I felt like I needed to do it to keep up with the workload. I know people who work 50+ hours a week regularly and get no additional compensation. Yes you can say they are free to leave that employer, but the expectation of unpaid overtime is found throughout American business culture and at all levels except for hourly employees and union employees who must be paid for the time they work, and who are often paid time and a half for overtime (although I have known some hourly and union employees who work additional time and just don't report it). The original poster says she works 12 hour days. Even if you are being paid for all 12 hours, that's a lot to ask. Wanting to receive text notifications from your child or your spouse during a 12 hour shift is not entitlement at all. That is completely reasonable in my opinion. Many states require short paid breaks for most workers for every 4 or 5 hours worked, so it's not unreasonable to expect that one should be able to take a break every now and then to respond to a text or deal with a personal issue.
This personal device in the workplace thing is actually the other side of the coin when it comes to mobile devices. For years I and many other workers have carried mobile phones, Blackberries and smartphones paid for by our employer so we could stay in touch with the office outside of regular business hours. Given the amount our work-lives intrude into our personal lives (even on vacation for some), many feel like they need to do whatever they can to manage both the work front and the home front more efficiently.
Sean