Example 1: The first sentence reads much better. When you read the example out loud, there are longer natural breaks after "hairbrush" and "donut" which requires a question mark.

Example 2: The first sentence reads better once again. It sounds odd, in this case, to start a sentence with "And".

Example 3: The first sentence is the best. This is solely because it is still the same person's thoughts, so no paragraph break is needed.

I hope this clears things up. If not feel free to ask more questions. That's how you learn.