My rescue dog runs and hides every time we come home or when she gets home with us after a walk. How can I make things better for her?

I adopted a 3 yr old cocker from an animal rescue center. I have learned that she has had 3 litters of puppies in two years. She is very timid. She walks on leash ok and can stay inside without being crated all day with no problems. The issue is: When we enter the home, she looks to see what the noise is and then runs to the opposite end of the home to hide. When we enter the home from being on a walk, she runs to hide. I have purchased toys that she will not play with during the day, but I have found them moved if we have been away. She will not come, will not eat if we are in the same room, will only potty if we are on a walk ( no yard use) She does not approach us, does not bark or whine. But will sleep in the bed with us, if I pick her up and put her in bed. She will not voluntarily get in bed with us. She is timid at some of the outside noise, but is getting better. We walk twice a day. Where do I start and what should I do? Thanks for the info.