Anyone Experience with Abused Animal?

Ruby was tied up in the rain/snow with no shelter and left hungry and cold for who knows how long. She was rescued from the situation, fostered for 2 months, and is approx. 8 months old or less. We've owned her for a month. She is not spayed.

We have never yelled at her or been agressive because of her issues. She just gets lots of love and positive training at our house.

That being said, we are novice dog handlers and are learning as we go, just trying our best.

Despite being fostered, she continues to have normal puppy issues, seems delayed in potty/poop and also has eating issues.

She will not eat kibble of any kind that I have purchased so far (wet or dry), will not eat raw the way that I have presented it, does not like to eat food off the floor or from her bowl and will eat food if I hand feed it that she will reject otherwise!

I was wondering if anyone who has experience with rescue/abuse situations could help me with her peeing, pooping, and eating issues.

The peeing issues are: if she is angry or upset, she will pee. She does not pee out of fear -- it is mostly when we've done something that she is unhappy about, like brush her, then she will go over and pee on something. We've NEVER reprimanded her in any way for peeing or pooping in the house. We'v ALWAYS ignored it and minimized it while simply cleaning up the mess.

The pooping issues are: she almost always refuses to poop outside, no matter what we do. We've used a command, and that did work for a bit, but now the command seems to make her angry?? She will look at us and sit down and not go. She will hold it and then if we look away for a SECOND she will poop.