[simulacrum]

Is this normal and is there a fix? I use my desktop in the bedroom which is connected directly to the router under the desk via cable, and my sister has her laptop which also uses the connection from the router with its 2 antenna's.
Whenever were playing online at the same time, every now and then both our pings will rise for a few seconds and drop again, really annoying lag.
Is there any fix for this? maybe her being closer to the router will help? not to sure, hope anyone can lend some advice.