Owner wants me to do a meet and greet with their house sitter?

It happens. I have had that happen only couple times when their preferred sitter had an emergency and he needed someone to cover the selected dates. I met with their Rover sitter instead, she gave me keys and instructions. Nothing weird about it. It also happens when a sitter must cancel unexpectedly, and then Rover reaches out to sitters to ask to cover this job. I also met up with the sitter who had to leave, and she gave me instructions and keys.

But Rover will always tell you if you DO NOT feel comfortable, just refuse the job. That's what Rover customer service told me. But i had no issues with it. Life happens, people quit last minute or their plans change.

That’s unusual. It would’ve been far better if she had met with both sitters in advance and started to build a relationship with both sitters in case she needed an alternate when one wasn’t available. Some people just don’t think forward enough.. It’s up to you if you want to help her out. If you decide to do it, the sitter and dog should meet you outside first (like you would with the owner). Bottom line, if you want to do it, take the same precautions as if the sitter was the dog owner and it should be fine.

If it feels a bit too weird for you then just don't accept the booking. I've had to do something similar with a previous client since she had hired two people to cover the stay and split up services. The other sitter most likely has the rundown for everything you need to know and can give you keys or door code info. The owner should have been a bit more proactive and met with you both, but sometimes it doesn't work out like that