Airasia are the most stringent and often do weigh the case. If it is over the 7kg they can make you go back to check it in and pay for it.
Yes 7kg is little for a week, so 2 options, pack light and you can hand wash clothes or get washed cheaply here, or just pay for the checked luggage.
I have flown MANY times with Airasia. You may of course be lucky… if it’s only
***
kg they don’t bother.
You can also wear a jacket with pockets and put heavy things in pockets, wear the heavy shoes / clothes etc.