Feelling like a shitty parent (long post)

So it snowed where I live and my SO has two kids 6 and 7 years old, I'm almost 35 weeks pregnant getting to the point even if I do the minimum my hips and legs start bothering me. My SO texts me earlier to see if it was snowing here as he's at work, I send him a pic of the snow covered yard and he asked if the kids knew it was snowing. I said I don't know cause I didn't say anything to them and haven't heard them say anything about it. He was hinting at me taking them outside to play in it. Their boots are at their mom's because she hasn't send them back yet. I can't let them just go out by them selves as we live in a trailer park and have a pedofile that lives across the street, and at almost 35 weeks I really don't feel like going and standing outside while the do nothing but make snowballs because we don't have a sled here and that's about all the snows good for.