On egg "not eating"

[Sunny-Boy]

My female Jessy is staying in her nest box on her egg and will not leave the box to feed or poop" 20 hours now"
The male Sunny is having no luck feeding her either. She seems healthy enough but she's never done this with her previous 5 clutches. Should I remove her egg ?

 

[HeatherG]

I’m not sure about the egg; is there room to put some food in the nest box? Maybe she’d eat it in there.

 

[Sunny-Boy]

Thanks for the suggestion, i'll try placing some food in the box