The gong show

How can you tell if a hen is an internal layer? How do you know if she is an internal layer?

I have a maiden hen who has a mate. The last time I saw them couple was feb 24 and about 3 days ago I noticed sje has an egg bum and saw a large poop the size of a penny. It seems each day she has been out of the box 2 or three times, has a comciderably larger than normal bm, a quick drink and snack. Them she goes back in the box. She is showing no signs of egg binding, but I'm going insane wondering of there are going to be any eggs laid. She stayed in the box all night last night for the first time. Right now she is out for her last night time break and was hopping back and forth in one spot like mad. Her sweetie gets quite beside himself when she is out... Tapping the box and gently herding her to it. Can anyone PLEASE tell me if she is going to lay or should I just give up and remove the box? (which she is back inside again now) this is driving me crazy!!!!