What Makes a Good Supervisor?

Is it being mean to your employee? I'm having one of those mornings at work. I have been really stressed out lately and my supervisor is really just adding to it. Two weeks ago from yesterday, she needed me to screen some viruses to be shipped. Normally, I could get these done in a week, but due to other circumstances requiring my time, I was unable to get them done quickly.

The biggest reason is that I have a work study student I've been training. Her first week was last week and she was here for about 6-7 hours over 3 different days. That in itself takes time, but I had to prepare for her too. That makes sense, doesn't it? Prepare for training a student? A sophomore who has yet to have a microbiology course. Who has no idea what any of the procedures we do are and has never held a pipette before. Is there a limit on the amount of time I'm supposed to take to prepare for her? I've never trained anyone before so this is new to me. It’s been a little overwhelming. I remember when I started as a student and had no idea what the heck I was doing. So, I decided to be detailed and to plan for the time she would be here. Seriously, I don't even make a plan for myself for the week until Monday, so adding training on top of that...yeah.

Anyway, that has taken a lot of my time during the last two weeks. Plus, this was a short week and I was sick on Tuesday. My supervisor didn't say anything until yesterday when she asked if I was done screening them. I told her no, but they would be done by Friday. Then today she sends another email asking which procedures I've performed on them and saying it's been 2 weeks since she emailed. It shouldn't take 2 weeks to screen "3" viruses (it's 4, actually) and that this needs to be a priority. Then, she so nicely added, "Honestly, this should be done within 1 week." Was that necessary?

Am I overreacting? I realize as my supervisor she can determine when things need to be done. She gives me a task and I do it. That's how the chain of command works. I get it. But, to me, if after a week I wasn't done and she had a problem with that, then shouldn't she have said something? She asked me about it last Thursday and I told her that I would be finishing up this week and she didn't say a word. That was her opportunity to say "Hey, it's been a week and I really need to ship these so do you think you can get them done by (insert day)?" instead of waiting for another week and then sending me an email saying she thinks they should be done.

She gives me things to do and never gives me a deadline or an estimate of when she needs them. It's not until she's annoyed that they're not done that she tells me, always by email might I add, and that just stresses me out more. And she always puts in a little something extra that comes off as rude. She's not a good supervisor. Her position doesn’t allow her to supervise people, technically, but I was hired to assist her so I guess that makes her the boss. I really need a new job.