Found a dog, contacted their owner but showing no interest in wanting her back?

While my brother and his friend were out playing soccer this lonely pup greeted them. They noticed she had a collar and dog tag so they called the owner but no answer. A couple more attempts and text messages later, still no answer. It would ring a few times but then it would say it's been forwarded to voicemail. We thought it was odd, but we took her in and decided to try again the next day if they haven't tried calling back. Well, two full days later and several attempts at trying to contact the owner we get no response. Earlier today, my brothers friend called us and stated that the owner messaged him back asking if he still has their dog. He told them that the dog is with us and gave them our house number to call so we can arrange something to return their dog. We waited and still no call. I tried calling them back and I texted them. I have an iPhone so when I sent the text it sent through iMessage. They read it almost right away saying "Read 5:00 PM" but no response. I saw the little bubble come up as if they were typing but they decided not to reply because I didn't receive a message back. They did not bother to call me back either. So now I do not know what to do, it doesn't make sense that they ask if we still have the dog, but won't respond to calls or text messages so we can return it. I absolutely don't mind caring for the dog in the meantime, but can I legally find her another home? I already have a dog that doesn't get along with her unfortunately.

Text them and see where they live and drop it off. You can't LEGALLY re-home the dog since you know who the owners are and you made contact with them. Call them and say come and get the dog or I will re-home it. They might get the dog then. If they don't surrender it to a shelter and let them handle it.

You can legally turn her over to a shelter and the shelter will attempt to get in touch with the owners and if they can't they will adopt the dog out…

You turn the dog over to a shelter or a rescue. You can't legaly own the dog or sell it since its not yours. You KNOW the dog has owners.

Hand the dog over to a shelter or a rescue and let them take care of it

"can I legally find her another home?" NO!

You must turn it into a shelter/rescue where it will get the care it will need, provide the owner info, then it becomes the shelter/rescue problem as to whether to return it and/or adopt it out.

Keeping the dog and/or re-homing it yourself you maybe arrested and/or fined for stealing.