How to Connect?

So, i've been trying to connect to my steph mothers computer. First i tried to get her ip adress without going on her computer's cmd.. wich i don't think turned out that okay. I typed arp -a -n in my Iterm2 it gave me alot of ip-adresses yet there aren't alot of computers on my network so i thought that was a bit strange.

i tried to ping some of the ip's to see if they were online, most of them were. When she turned her computer off, i tried again and hopefully notice that one had turned off, which it did, but when she turned her computer back on, the ip stayed offline.

after some struggling i finnaly thought i got her ip, went into my kali and typed "/etc/init.d/postgresql start" and added her ip in the Host > Nmap scan>Quick scan (OC detect) it popped up on the screen above. Scanned it again, and clicked attack>find attack then started a Hail mary. right clicked it but... no meterpreter 1 was there? Can someone help me to get the right ip? pls, because i have a feeling arp -a -n didn't work. Thanks !

Joe out.