D.P.
You and your little girl have experienced a lot of changes. I whole-heartedly agree that you should find a reputable child therapist or psychologist for her. In addition, IMHO YOU need to get some counseling as well, or at the very least find a support group to connect with in your area.
There a many good resources at your disposal, so take advantage of them during your time of adjustment, grieving, and trying cope with all that's going on in your life.
After my grandson's daddy died, he was just shy of turning three, and his behavior changed dramatically, showing fits of anger, acting out with violence, bouts of crying, etc. The best thing that happened was a fantastic counselor my daughter found, and she interacted with the family, since daughter and grandson were living with us. She gave us good sound advice, worked with my grandson, and we learned how to "defuse" and communicate with him at HIS level. We saw extraordinary results after only two or three sessions, and after 3 months of weekly visits, then two monthly sessions, she signed him off, but told us to call her whenever we had any issues concerning our grandson.
YOU are also suffering, whether you are able to acknowledge the depth of it or not, you've had to deal with the loss of a marriage, a husband and provider, the transition of having to move, stay with family, look for employment, etc. So don't neglect YOU either!!
My own experiences have taught me to not be afraid to seek help. It can lift the burden, help you understand your own feelings, and give you valuable tools to use the rest of your life, coping skills, and can elevate your self-confidence.
God Bless and hope all turns out well for you and your little one.
Oh, I want to add that being near to extended family is usually a big plus, as you can build a support system between them, your friends, and church, assisting you with going forward with your life.