Hi K.!
My heart really went out to you when I read your post - you are doing such a brave thing and it is easy to see how much you love your daughter.
My situation is not the same as yours, but my daughter is biracial, so we don't look like most of the families around us (although, just like single parent families, our family is certainly not odd or strange nowadays).
I like the advice below about finding single parent families to hang out with. I have a friend who is raising her son all by herself (no dad in the picture) and she is part of some group. I'll try to find out the name of that group and let you know.
Other advice would be:
Find books that show families of different combinations - single mom raising children, grandparents raising children, aunt and uncle raising a niece/nephew and so on. I have been showing my daughter multiracial books since she was about 1 and talking about the different skin colors and races within a family and she just adores these.
Whenever you see a family like yours on TV, point it out to her with excitement. I have done this with my daughter - I'll say, "look! That family is just like ours! The mommy has light skin and the daddy has brown skin."
I don't know if she likes Sesame Street, but they are great for showing a wide variety of families, races, and people with disabilities. Many times, I've seen them showcase a single mom raising a child or children. The child usually narrates, something like, "I live with my mommy and brother. I love the weekends because that's when we go to the park" then they'll show the mom and two children having a picnic in the park.
One last thing - if you are feeling sad about the fact your daughter doesn't have a daddy and you sympathize too much with her, she may come to the conclusion that her life is really bad without a daddy.
It's a hard line to walk - on the one hand, you're human and what you went through must have been heartbreaking. You also don't want to dismiss your daughter's feelings.
Yet, you also want to make sure that you maintain an upbeat attitude about your life, the fact that you're a single parent (for now, at least!) and that there are literally millions of little girls and boys all over the world being raised without a daddy.
I was humbled by the courage you have shown to protect your little one and I wish you all the best.