This is a slightly younger Petra, still getting used to her somewhat unique condition and a little embarrassed about the all too obvious effects on her body.

Another picture from  mehndix. I really like how this one came out, just as I was hoping it would.

EDIT: I realized that I had hinted about her uniqueness in other pictures, but have yet to offer a fuller explanation.

This lovely young lady is in fact part plant, which explains her green coloring as seen in other pictures of her. This gives her some ability to use photosynthesis for energy, although it provides only a small portion of the energy needed to lead an active life.

The second, more noticeable aspect is that she produces melons. These fruit grow inside her, leading to the pregnant appearance seen here. Being more simple than cubs, melons can grow a lot quicker, resulting in a Petra swelling faster than she might expect. This is further complicated by the fact that the number and size of the melons can vary greatly. Her last batch provided a much smaller bulge, so the girl is rather caught off guard by this set.

In this picture, Petra is still getting used to things, and is rather embarrassed to find herself so large, especially without adequately fitting clothing. Later on, she will get a lot more confident about herself,k and she will also learn the different factors that can effect the size and number of melons, including amount of sunlight, water, and certain nutrients found in foods. This allows her to better control, or at least predict, the size of a clutch, letting her be a bit more prepared than in this instance.

She doesn't know if her womb can gestate cubs as well, or only melons. She's not yet been curious enough to try.