Hi there and welcome to YT ! I see that you live in Clovis, that is not too far away from me.. I am home all day and would be happy to be a babysitter
Setting up a little home in the bathroom should work for a while. 7 weeks old is very young to bring home A yorkie puppy. And she needs A lot of love and attention from you guys right now. Make sure she is eating and drinking to avoid any hypo. attacks. you do not want her to become to stressed out because then she may not eat as well as she needs to .
Definately leave A blanket or something that has your scent on it for her , she will feel more secure . Make sure that she is kept warm too, and as comfortable as possible.
Is their anyone that could come over and check on her while your gone working? A friend or family member? Maybe during lunch hour you or your wife could go home and spend time with her? Just A thought. You want this little puppy to feel secure and safe. She needs you guys more then ever right now at such a young age.