what to do about my 10yr old daughter acting out

I think you should try a sympathetic approach rather than coming down like the arm of the law. She's in obvious distress and needs help and understanding.

Welcome to the pre-teen years!

It is said the 10 year old of today is the 15 year old from just a few years ago. So her behavior is not unusual, but is a little exaggerated. (Drama queens in bud. )

I’d suggest a change in counseling. Find a counselor who deals with adolescents. Make it family sessions, too.

Just curious - what kind of student is she? Any learning difficulties?

IANAD

Your daughter has a lot of stressors right now.

* Your husband's untimely and probably traumatic death
* New house and room, different from the old ones
* New neighborhood
* New school
* New people to meet and probably no new friends
* New teacher
* New way of doing things
* New teaching methods, potentially making her ahead of her classmates in some areas, and behind in others
* You've just started a new job, and you probably aren't able to spend as much time with her.
* She's also a tween, and her body and mind are changing-- whether you or her are ready, or not.

BTW, you have a lot of those same stressors. The difference is that you're the grownup. You have probably developed more mature coping mechanisms. And you have the power in the relationship.

No wonder your daughter is acting out.

Some ideas:

* For whatever after school activities she enjoyed before, see if you can get her into something as similar as possible ASAP. Like if she was captain of the soccer team, get her into intramural soccer. She won't start off as captain, of course. But at least she will be in a position to do something she enjoys, with kids who like the same thing and would be great candidates for friendship.
* Take her shopping for some new things for her new room. The size, angles, views from the windows, and placement of the windows and doors are different from the old house. I am not suggesting a new bed or other furniture right now. Rather, I am suggesting paint if that's possible (I don't know if you rent or own the place). Curtains. Comforter. Throw pillows. A few things that are purely decorative with no practical use, like a sun catcher for her window, or posters of her favorite bands. Don't change anything she doesn't want to change. The idea here is to meld the old and the new together, to adapt to her new surroundings-- and the new her. And she chooses. If you can afford it, then it's her choice. She lives in her room. You don't.
* Clothes! Same thing. Does she need bras that she didn't need before? Heavier or lighter things if the climate is different? The style in her school is undoubtedly different-- even if she wears a uniform. If she runs into her classmates on a Saturday, she's not going to want to be caught in last year's fashions. Forget if she's never been into that, or even if she tells you she's not. She is the new kid and her age group is getting to be obsessed with this. She will want to fit in, even as she puts her own spin on things. And again, the only opinion that counts is hers. If you can afford it, and it fits the school dress code and it fits her, then it's hers. Never mind that it's a color, cut, or fabric that you would never choose. She's the one who will be wearing it. But if the care is difficult or expensive-- make sure she knows that's her responsibility (do tell her this before you get to the register).
* Did she make money in your old neighborhood? Then she may be missing that pocket change. She's probably too young to babysit, but can she weed a garden, rake leaves, shovel snow, or clean out gutters? I'm not suggesting anything beyond neighbors who are, let's say, three houses down on either side or across the street. Nothing more than an hour a week if that. Of course she has to get her homework done. And maybe she doesn't want to work. But it's a way to do something that isn't school or home stuff, plus she makes her own money. It is a small piece of independence. As she gets older, those pieces of independence are going to have to get bigger. This is an easy way to start.
* Find out about any help she can get with classwork, and see if you can help her, too. She needs to get up to speed and used to how things are done at her new school. She is flailing in the deep end and needs a scholastic life preserver.
* Find out what after school programs are out there. She may want to try something new, or even reinvent herself with her new peer group.
*And try to find ways to spend time with her if you can. Right now, she probably feels like she's only got 1/10 of one parent. Can you do something fun, just the two of you? Go see a movie. Hit the beach if there's one. Get manicures together-- whatever works.

You may want to consider a few of these ideas adapted for your own use, BTW.

Is this all expensive? Yes. Time-consuming? Yes. Difficult? Yes.

But you have both been through a lot. And she has looming puberty on top of everything else.

Expect this transition to be hard.

You are punishing her for having real emotions such as anger and frustration. These emotions are necessary to be acknowledged but not to this extreme. Taking away her electronics isn't going to cure her anger, it's only going to get more exasperated. You're teaching her to push down these emotions or else she gets into trouble. Acknowledge the anger and teach her it is ok to be angry, just show it differently. She can have an outlet to release the physical part of being angry:

-Have a pillow fight
-Smash pumpkins & roast the seeds
-Put her in boxing or karate classes
-Teach her to run, cross country or hurdles
-Allow an half hour a week to specifically slam a door of her choosing
-Go to a secluded park and scream (not obscenities)

Show her too, that YOU get angry sometimes. It's ok to show her that it's common and sometimes talking just doesn't cut it.