$300 · Is Tessa the right girl for you?

Tessa, approximately 6 year old German Shepherd that I brought into my rescue from a high kill shelter in California. Soon she will be ready for a place to call home. Spayed, shots are current. Tessa is a relaxed dog and mainly just sleeps while in the house. While outside, she will wander the yard and will eventually lay down under the plum tree in the shade. She hasn't barked at people walking by and seems more curious than anything. She has been fine with every human she's met. She has not been introduced to children yet and perks up when she hears the neighbours kids. I've never seen her dig in my yard. She appears to like going for car rides. She gets along fine with the two resident male dogs but isn't too much of a fan of my female and that is likely due to my female being crabby with other dogs. She doesn't know any commands other than 'sit'. Her leash manners are poor and I suspect she was never walked before. She is getting better on leash now that she has a better understanding of what I want from her. I don't know if she has been crate trained but she is sometimes crated here. The only time she's protested is if she can hear me in another room. Now for the not so nice stuff! She looks to me like she would get off property if given the chance. She is never left unsupervised outside and while outside, she drags a 30' long line to be on the safe side. While in her foster home in California, she got off property 3 times and she chewed a pair of flip flops. Sometimes when I've left her in the house she would bark in protest and would settle after a few minutes. If she could hear me outside, she wouldn't settle. I felt that she was just being bull headed. She has undergone a lot in the past 2.5 months and everything is very uncertain in her world. Once she is in a good routine and has rules to follow, she will be a pleasure. Because she's a fairly mellow dog, I don't anticipate her to being a needy dog. The only concerns I have of her is not knowing how much she will try to get off property or if that is a behaviour because she has no idea where she is and she wants to go home. I have a lesser concern about her chewing a shoe as I've not seen her do that here.