Help please. We go camping every other weekend (same campsite) and the past two times DD (4 in two weeks) outright refuses to sleep.

Here is our camper for reference:
https://my.matterport.com/show/?m=HDxLBuDr7Ly

She sleeps on the lower bunk, DS sleeps in a PNP where the booth table is, I sleep along the back of the dinette, and OH sleeps in the bedroom.

Here are things we have tried that did not show improvement:
- Window film on the windows so she can't look out
- Curtain so it is more private
- Sleeping bag so it is more fun to sleep
- Letting her fall asleep before, after, and at same time as DS
- Bedsharing

Next trip (Friday) I am going to try her toddler cot in the kitchen (so across from DS). We keep the propane off so no danger in her being close to the stove.

I am willing to hear any other ideas. Everyone is miserable when we play hard all weekend and then she (and therefore everyone else but DS) doesn't sleep.