Hi there, I too have a little naughty girl aged nearly 8 months. She has been through skirting boards, mats, bowls, practically every toy owned by her and older sister Poppy... the worst was when she chewed the heater's cable...
could have killed her but I was too glad she didn't electrocute herself doing that!
I work full time too and on some days my partner works from home and on others the dogs are alone for a few hours. I'm lucky I don't work too far from home so I can pop in at lunchtime and let them out. Poppy has the run of the conservatory but we learnt soon enough to not let Willow run free in there. She is crated when we are not home. The crate is big enough for her to move around in it and we leave her in there with water, toys, chews, kong, ball with treats in... She seems to be fine in there but on 2 occasions when we went out in the evening for meals (latest one was last night!), we came back home to find Houdini out of the crate. The first time she had litteraly shredded the brown rug that we wipe our feet on when we come back from the garden and last night the water bowl was upside down, there was newspaper everywhere and the skirting boards (what was left of them anyway) was sprinkled everywhere. She knew she had done wrong as she didn't want to come near me when I called her!
We are looking at buying CCTV equipment to find out exactly how she does it (we don't believe her big sister is involved in the opening of the crate).
Other than that she is a perfect little darling when we are around (although Poppy probably disagrees!)