New adopted cat Lucy

[Lucy's New Mom]

We have just made a new home for Lucy, our friend's cat of 5 years. She roamed freely in and out and was very attached to her 80 year old owner and little house.
We have a big house and 4 of us here, plus a gentle dog that Lucy knows well as he has stayed with her before several times when we are away. We put in a cat door just like her old one and kept her in for the first 3 nights. She hates it inside & got out and stayed out for 2 nights. We coaxed her back in 3 times, but she found an open window in a bathroom and escaped again - then we didn't see her at all or hear her for four nights - thought we had lost her.
She came in last night through her cat door, which we had made one way in only -- but ran for the window again and got back out before we realized she was back.
No she came back again (at 2am) tonight for a nibble, and we had closed everything -- so I cuddled her for an hour and have put her back in the laundry room with all her things & food, etc. (where she stayed the first 2 nights). She is not happy. If we let her just come and go, it's clear she stays nearby, but seems to becoming more and more wild. She doesn't come in to socialize at all - just sneaks in, in the middle of the night to eat and runs back to the bushes. We live on a farm, very private, and she is fairly safe outside here and has lots of shelter in bushes around our house -- the way she was used to at her old house.
Suggestions on getting her to become part of our family, and not be too furious at us for inprisoning her?!
Thank you for any help... I just don't know what to do.
Lucy's New Mom