I think my friends dog is depressed

Hi all, sorry if this goes against sub rules, I’ve never posted here before. Anyways, I’m dogsitting for a friend this weekend, and like the title says, I’m worried their dog is depressed. It’s like no matter what I do, she doesn’t want anything. I’ve dogsat for them before, and for much longer than just a weekend, so it’s not like I’m a stranger. I just don’t know what I’m doing wrong.

I’ve made sure her bowl is full, but she’s not eating (she’s a picky eater so I’m not too worried about this); I’ve offered to let her outside to use the bathroom, but she won’t go; I took her for a walk, but it’s really hot out and she started slowing down so it wasn’t that long; and I’ve tried playing with her, but she wasn’t that interested.

It’s like anything I try to do she’s just not feeling it. All she really does is just stare at me, but when I turn my attention to something else, she starts getting closer. Right now she’s just laying down on my legs, but she’s been laying down most of the day (I had to run home for a few hours to take care of some errands). I really don’t know what else to do.

Am I paranoid for thinking this way? Is this just normal dog behavior? I’ve never owned a dog before so I don’t really know how things usually work, but I’m doing my best to follow the instructions my friend left. I managed not to kill her last time I dogsat so hopefully I’m doing something right lol. Thanks in advance for the help!