Sharing Won't Work? Can't Find PC in Network?

Hi,
so I have 3 PCs
-PC
-Girls-PC
-Boys-PC

PC is the homegroup creator , Boys-PC is mine , Girls-PC is my sisters'.

So basically , Mine Can see PC , Girls can see PC , and can see mine , PC is able to see Mine and Girls.

The problem is , that My PC doesn't See Girls-PC!

I went through the network options and this is what I found:

Local Network:
-Boys-PC
-Admin-PC (Girls PC Previously before Upgrade to Windows 8)
-Xbox360
-TabletDevice

All Networks:
-PC
-Admin-PC
-Admin-PC
-Girls-PC
-Boys-PC
-Boys-PC
-Boys-PC
-Xbox360
-TabletDevice
-hTC Photon

the 3 PCs are running Windows 8
the 3 PCs are in the same Homegroup
the 3 PCs are in the same Workgroup : WORKGROUP
Same Region and Time Zone
Same Clock
Same Homegroup Settings

Network Discovery is on and set to Automatic

Homegroup by Windows is set to : Use User Accounts instead
Reason: All 3 PCs use the same username : Admin , and Backup .

PC has a password on Admin , Boys-PC has a password on Admin , Girls-PC Doesn't have a password on Admin , but has a password on Backup.

So....where's the problem?

I tried to leave homegroup and re-enter , same problem
I tried to leave on both PCs , but this time , I created a new homegroup on my PC , and on Girls-PC it says No Homegroups Found on this Network.

So I left it and did the homegroup on Girls-PC , now my pc says the same,

However PC is running fine , and no problems.
PC : 192.168.1.105
Mine: 192.168.1.145
Girls: 192.168.1.144

DHCP Reserved!

So what should I do? Under Homegroup in Windows Explorer it keeps telling me my/Girls is unavailable at this time , is the problem because the Admin has no password? Or is the problem because the usernames are the same?

Thanks



Update:
MY PC = LAN
Girls = WLAN
PC = WLAN , Identified as LAN in DHCP settings

I'm now able to ping both PCs using the IP and the name by disabling completely the norton360's Firewall.
But the problem still remains , which is Whenever I go to the homegroup I have an option to create only , no join (PC is currently shut down which is the holder of the homegroup). And also Girls-PC after a restart can't find My PC...

I created a new user called Sharing on both PCs with the password sharing , still no help.

Changed the IPv4 to NetBIOS over TCP/IP
In Homegroup Sharing Used Users instead
In Folder Options Disabled the Use Sharing Wizard

So what should I do? I want to reboot the router but in a safe way , any way to do it?
Note: I do have an Xbox360 but It's not in "My Computer" any Ideas?