I got Zack when he was 16 weeks old and i had decided there was one sofa he couldn't go on, the dark blue soft flanel-like slip cover one, the slip cover can only be dry cleaned and i don't like dry cleaning fluid, so, i didn't want the hairs shed on that one. I never expected that he would chew it or put holes in it, just shedding.
The cat isn't allowed on it either. Why they obey me on that, i'll never know. I guess the cat just has other places that satisfy her, but she liked the sofa, so i dont' know.
When i got zack, i also got a book called Puppy Preschool, and the author said to use the word "nhaaah" when redirecting a puppy because he said you should use behavior similar to a mother dog, when socializing a young pre-training puppy, and mother dogs, he said, tell puppies to stop doing things by going "nhaaah." I used it for everything, i was so surprised when i first started doing it that it really worked. I've had dogs in the past and always used "NO." "nhaaah" worked way more consistently, immediately, whereas 'no' didn't seem to be understood at first. Interesting.
I said nhaah when he thought my tennis shoe was another one of his dog toys and he began to mouth it, and he never touched any of my shoes again. these results are way beyond my expectations. The only behavior it didn't work on was zack running up to the cat and bonking her and sniffing/licking her butt. His urge to do that was way too strong.
But it did get him to get off the blue sofa and stay off. Even when i occasionally lay on it, he won't try to get on. Normally i sit in a reclining chair and he can get up there all he wants, which he only does when i'm on it, so he's in my lap. but he usually lays on the love seat. I have been surprised that he learned this right from the start. He really wanted to go on the sofa, but he also seemed to want to do what i said. i don't ever find white hairs on it, so i assume he doesn't go on it when i'm not home.
But then when he was about 8 months old, he suddenly got really sick, it was so scary, he suddenly changed from playing and running around to just laying all day. He would get up to walk and would go a couple of steps and lay back down. He was scratching and rubbing his face, but otherwise, he didnt' do anything. He appeared depressed and as if he felt very bad. He did have a good appetite, but didn't readily walk to where the food and water were--the main problem seemed to be with walking around. I theorized that he might be dizzy or faint, or extremely weak, it happened overnight. He was like that for three days and then skin lesions came and the diagnosis was pyoderma and he started improving after that.
But on the first two days of it, i had to work, so i had to leave him. I left him in the living room where he would be most comfortable. The thing is, after all those months of not going on the blue sofa, when he got that sickness, he ONLY wanted to be on the blue sofa, and he acted as if he had never learned not to go on it. At first i tried to redirect him, but he ignored me, and at the same time, he was so sick, i chose to let him do it and deal with the consequences later. I put a sheet over it. And he stayed there constantly. A few days later when he was acting more happy and active, i started saying "nhaaah" again about the sofa and he readily accepted going back to how it was before. he stopped going on it.
Zack never showed any interest in biting any furniture except the rockers on the wooden rocking chair, i sprayed bitter yuk on it and went 'nhaah' and he stoppd. he never bit cloth upholstery. My cat used to claw the slipcovers of the love seat and sofa, she really shredded the one on the love seat, but it looks ok after trimming off the threads. But, so, i got this two sided clear sticky wide tape that's used for this purpose, and put the tape over the areas she liked to scratch, and it stopped the scratching very effectively. she didn't like that stickiness. Maybe this would work with dogs biting too? It doesn't show unless you're looking for it, it's clear.
i have pretty much despaired of persuading zack not to jump up toward peoples' laps whether they're standing or sitting. The breed was bred to be inclined to merge with people, like karlin said, this is how they are supposed to be, people bred them for this, telling them they're not supposed to doen't make sense to them. i've worked with zack on not jumping up on people when they stop to pet him when we're out, and he tries not to at first, but i can see his little inbred inclination coming through so powerfully and the more they pet and say "you are nice doggie" and stuff like that, the more the urge builds up, and then he kind of starts putting his front paws up. and saying nhaah or anything doesn't penetrate his brain well. it's a very hard one for him to get.
good luck with adapting your lily, she sounds fun.