Skins won't render on my LAN network for other players

What I expected to happen was...:
My sister's skin would appear.

What actually happened was...:
On my screen, She was Steve and I had my skin. On her screen, She had her skin and I was Steve.

Steps to Reproduce:
1. Try going onto a LAN network as this is when this happens to me (haven't been able to test on an actual server.)
2. Look for the other player(s) and see if they are Steve/have no skin.
3. Report to me if this happens to you.

Note
My sister is also running Windows 7, not sure what version of Java. We have also had a LAN with a Windows XP & Windows 7 and the same result happened. The screenshot where you can see all of my skin has no resource pack, the other one has the Faithful 32x32 resource pack. Another random note that doesn't affect the skins is for some reason I had my language on Japanese.